Alfonso Cornish went to work for the leader of Prince George’s County in 2003, believing that his newly elected boss would set a bright horizon for the country’s most prominent African American suburb.

But soon after settling in as a senior adviser, Cornish found himself growing uneasy with then-County Executive Jack B. Johnson (D). Month after month, Johnson doled out jobs and consulting contracts to friends, a number of whom seemed unqualified.

Cornish’s discomfort grew when he discovered a security company sweeping Johnson’s office suite for wiretaps, a search that included his boss’s car. Toward the end of Johnson’s first term, a high-ranking colleague told Cornish that the county executive had predicted that he would become wealthy before leaving office.

“That’s when I knew I had to get out,” said Cornish, who resigned in 2006. “I’m probably the only person who left who said, ‘He’s going to jail.’ You have a sixth sense about things.”

Cornish’s sense was dead on. As Johnson prepares for his sentencing in September on federal corruption charges, the story of his rise and fall is one of a consummate outsider becoming the gilded insider, a man who allowed greed and hubris to destroy everything he’d built.

As he ascended the heights of power in Prince George’s, Johnson promised nothing less than a new social order. He told audiences that he’d dismantle the “old boys network,” shorthand for the white developers, lawyers and lobbyists who had long feasted on government work. Johnson vowed to replace them with people such as himself, the outsiders, the African Americans and new immigrants — Indians, Pakistanis, Asians and Africans — who hoped to become players in the county’s political class.

Across two decades of public life in Prince George’s, Johnson was never the chosen one. He was the successor to two Democratic politicians who achieved history in two separate elections, Alexander Williams and Wayne K. Curry, the first African Americans in Prince George’s to become state’s attorney and county executive, respectively. They were revered for their oratorical skills and polish. Their rise was celebrated by a broad coalition of black and white voters.

Trajectory to office

Johnson’s path, though, was propelled by blue-collar and middle-class blacks, a core who believed that he told the truth about brutal police practices when the establishment was too afraid to speak up; who appreciated his fastidious dress; and who thought they knew him because he appeared at their barbecues, churches and hospital beds, kissing their cheeks and reminiscing about growing up in South Carolina.

His path from poverty to a brick colonial outside the nation’s capital was their story. His success represented their highest aspirations.

Yet, away from those crowds, in conversations secretly taped by federal agents, Johnson built a brazen web of patronage, cronyism and corruption. He talked of shaking down businessmen for hundreds of thousands of dollars. He talked of using his wife as a political pawn to help his allies. He talked of getting his share.

On a warm morning in November, less than a month before he was to complete his second term, federal agents arrested Johnson, adding a humiliating coda to a political career he had started building more than 20 years earlier. Six months later, he pleaded guilty, admitting to taking at least $400,000 in bribes.

“It’s a Greek tragedy,” said Doyle L. Niemann (D), a former Johnson campaign adviser who is a Prince George’s prosecutor and House delegate. “Jack is fundamentally a decent guy who rose out of a different environment, achieved success, overcame tremendous obstacles and made something of himself. At some point, he lost sight of what he really believed in and allowed himself to be not just tempted but led astray and do things that he knew he shouldn’t do. The result is his downfall and the negation of everything he did and achieved.”

How Johnson came to squander what he built is a lingering question for those who supported him for years. They claim no naivete. They knew he had been controversial for most of his tenure. They knew that his opponents had derided him as a poor manager, panderer and demagogue.

But a felon?

Did he really believe in that progressive multicultural vision for Prince George’s? Or was that rhetorical cover for enriching himself?

“I’ve lived long enough and been involved long enough that I was pretty confident that I was a good judge of the environment and situation,” said Henry T. Arrington, Johnson’s former campaign chairman. “I feel like a fool, an old fool.”

‘He became arrogant’

To the east of the District, Prince George’s is a mix of densely packed towns, neat suburbs and sprawling farms. For generations, its population was dominated by white factory workers, farmers and federal bureaucrats drawn to the abundance of relatively inexpensive housing. In the 1970s, whites departed and waves of African Americans arrived, a migration eventually joined by Jack and Leslie Johnson, who settled in a neighborhood of black professionals in Mitchellville.

Johnson’s new home was nothing like the segregated South in which he had grown up, on a sea island off the coast of Charleston. He was the fifth of 10 children. His father was a longshoreman and a farmer. His mother worked as a maid. He attended an all-black high school, swam at a beach frequented only by blacks and, as a child, viewed whites with mistrust. “They were people that use us,” he told The Washington Post in 2002. “They were the power, and we were the servants.”

After graduating from Benedict College, Johnson earned a law degree at Howard University Law School and moved to Prince George’s, which for decades had been ruled by a clique of white power brokers. As with any political machine, the pols handed out contracts to favored law firms and consultants. Over the years, a number of embarrassing scandals erupted, including one in which a developer, in exchange for a favor, gave a $3,500 tractor to a county commissioner.

“Real estate development is by far the largest industry in the county — it’s what oil is to Alaska,” said Timothy Maloney, a Greenbelt-based lawyer and a former state delegate. “Most public officials are fundamentally honest, but there has been a persistent strain of the political culture that is really not motivated just by public service. You can’t blame personal misconduct on the political culture, but it certainly provides context.”

Johnson had vowed to prove his innocence before his sudden guilty plea last month, and he has not explained his actions. His attorney, Billy Martin, said he would ask Johnson whether he wanted to comment for this article. Martin never called back.

An ambition

As the county’s demographics shifted in the 1970s and ’80s, Johnson joined a group of blacks organizing a push for political power. Williams, Johnson’s classmate at Howard, was the first African American elected to county-wide office when he became state’s attorney in 1986. Williams chose Johnson as his top deputy.

Arrington, then Williams’s community liaison, recognized in Johnson the ambition to climb politically, the first step being to become state’s attorney. “We were mapping it. He was next,” Arrington said. The men shared a political vision, he said, their goal being to “integrate the social, economic and political structure.”

In 1992, the New York Times Magazine published an article about the evolution of Prince George’s titled “The New Black Suburbs.” For its cover photo, the magazine chose Jack and Leslie Johnson, the smiling couple and their two boys on the green lawn leading to their brick home.

“It raised Jack’s profile,” said Gloria Lawlah, a former state senator. “It made us feel great that the entire nation could read about our community. We were doing it for ourselves, and he became the leading face for the identification of Prince George’s County.”

When President Bill Clinton appointed Williams as a federal judge in 1993, the county political establishment did not choose Johnson as the successor. “He told me the same story over and over again about Alex Williams and how they were overlooking him for state’s attorney,” said a former aide who went to work for Johnson years later. “He resented it.”

But Johnson didn’t need the establishment. By the early 1990s, he was building a political network, greeting voters during daily drop-ins at restaurants, barbershops and bowling alleys. He marched in parades, formed alliances with ministers and attended civic association meetings. He listened to small-business owners — Koreans, Indians, Pakistanis and Africans — who were concerned about crime in the strip malls where they owned their shops.

“He saw them as an untapped political resource,” said Arrington, who arranged many of the meetings. “No one had galvanized them.”

In the 1994 campaign for state’s attorney, Johnson racked up twice as many votes as the runner-up, stunning everyone in the Prince George’s political world except the county’s new prosecutor.

As state’s attorney, Johnson was well known for prosecuting police officers, albeit unsuccessfully, a tactic that helped him build support among community activists and in working-class neighborhoods, where relations with the police department had long been frayed. But Johnson’s aggression toward police also made him the target of criticism from the police union, judges and sometimes his prosecutors.

In 1997, during a period in which 40 prosecutors left his office, Johnson clashed with his top deputy, Steven Levy, after Levy advised him not to seek an indictment against a police officer accused of shooting his girlfriend. Levy, who had been close to Johnson, thought that prosecutors lacked probable cause and that the officer had acted in self-defense. After listening to Levy’s argument, Johnson fired him.

“If you disagreed, you were subjected to punitive action,” said Levy, who now practices law in Indiana. “He became arrogant.”

Vincent Femia, a retired Circuit Court judge, approached Johnson with an idea for expediting drug cases. “I told him there was a way he and I could save the county $6 million a year,” Femia recalled. “His response was, ‘What’s in it for me?’ I said, ‘I thought good government would be enough.’ He said, ‘What do I get out of it?’ I said, ‘I guess nothing.’ That was the end, and I walked away.”

Over lunches, Femia said, judges routinely grumbled about competent prosecutors quitting the state’s attorney’s office and Johnson providing no leadership. “He just was an absentee landlord,” Femia said. “He was running for another office. He was doing things for politics, and that was it.”

In 2001, as candidates jostled to succeed Curry as Prince George’s executive, the political establishment dismissed Johnson as an unsuitable heir to a man whose corporate-style panache made him a symbol of the county’s affluence. Behind Johnson’s back, political insiders made fun of his sometimes garbled speech. They predicted that he’d never raise enough money to win because he had no ties to developers.

Johnson laughed off the jokes about his speech — “I am who I am,” he once said — and expressed no worry about raising money. When the campaigns released their first fundraising reports, he had collected $100,000 more than the runner-up. A large portion of the money came not from developers but from the immigrant groups he had long courted.

The next spring, he declared his intent to run in a mass mailing to Prince George’s voters, writing that he had inherited his values from his parents, who “believed in hard work and discipline and keeping your word.”

“We need to start talking about values,” Johnson wrote. “About right and wrong and the importance of doing what’s right.”

On the eve of the Democratic primary, Johnson hammered away at the “old boy network.”

“Their time is gone,” Johnson promised. “It’s our time.”

‘He’s in charge’

As he took office, Johnson moved quickly to establish a reformist tone, appointing a former New York City police commissioner to assess the county police department. His aides branded his first major initiative as “Gorgeous Prince George’s,” a campaign to repair the county’s image.

As he talked of repaving roads and cleaning up trash-littered streets, Johnson took the first steps that would later draw the notice of federal agents. By the end of 2003, the county executive had accepted a $3,000 bribe from Mirza Baig, a doctor and developer with whom Johnson had invested in real estate. Baig was part of the contingent of Pakistanis who had long supported Johnson.

With his newfound power, Johnson tended to his acolytes. He awarded more than $3 million in contracts to 15 friends, including his personal attorney and his neighbor — a former sixth-grade teacher and the owner of a small technology firm — who got $200,000 in contracts to study global economic trends.

“Jack Johnson becoming county executive was equivalent to winning the lottery,” said a former high-ranking Johnson adviser who spoke on the condition of anonymity because she does not want to be associated with him.

His decisions sometimes confounded his advisers. He took from Cornish, for example, the responsibility of overseeing certain real estate developments. “These were major projects, and you question it,” Cornish said. “But you also say to yourself: ‘He can do whatever he wants. He’s in charge.’ ”

From afar, allies wondered who had Johnson’s ear. “One of the things about Jack is that he pursued his own path, he created himself, and he never had a team he was closely aligned with,” Niemann said. “He surrounded himself with people who were timid and afraid and unwilling to challenge and confront him.”

By 2004, state investigators had launched their first probe of the Johnson administration, asking whether he had threatened to withhold $5 million from the county’s public hospital if management did not hire his ally. The investigation ended without charges, leading Johnson to say he had been smeared. He threatened to sue anyone who took him on in the future. “I’m not going to be bounced around or punched on,” he said.

The next year, two administration officials were indicted on allegations of contract steering, one of whom eventually went to prison. Then state prosecutors asked about the two consulting contracts Johnson awarded to his neighbor, Wilbert Wilson.

“You can go fishing,” Johnson told reporters, “but you’re not going to find anything. I’m absolutely convinced that Prince George’s County, under my administration, is the most ethical, well managed that you’ll find.”

After arriving at the office on a weekend, Cornish discovered a security team searching offices for electronic bugs. “They were removing electrical sockets. It just shows you the extent of the paranoia,” Cornish said. At staff meetings, he said, the county executive lashed out at his advisers, more than once saying, “I know you’re talking about me.”

In 2006, three days before he was won a second term, Johnson took what prosecutors later said was his second bribe from Baig, $10,000 in cash. By then, the administration had sold two county-owned properties to the doctor and was about to sell a third.

Two years later, federal investigators raided the offices of two of Johnson’s advisers. Agents took papers and computer discs from the homes and offices of several Johnson associates. “I don’t have any information that anyone in my government did anything wrong,” Johnson told reporters.

Even after the raids and the ensuing chatter about impending indictments, Johnson used his power to leverage more cash from Baig. In his last year in office, Johnson helped get the doctor’s friend a hospital job, then said he expected a $50,000 payment.

Baig needed Johnson to get him more than $1 million in federal subsidies for his real estate projects. In mid-August last year, Baig handed the county executive $12,000 in cash. A couple of weeks later, he gave him $8,000 more. In September, the doctor gave him a check for $100,000.

In October, as Baig began cooperating with federal prosecutors, Johnson was winding down his administration, reminding audiences that the county had obtained a AAA bond rating on Wall Street and that National Harbor had opened.

“By any standards that you look at it,” he told a reporter in a farewell interview in late October, “we are making tremendous progress.”

Fifteen days later, federal agents videotaped Baig handing Johnson $15,000 in cash. The agents then recorded the county executive ordering his wife to flush the $100,000 check from Baig down the toilet.

After his arrest, Johnson issued another denial.

“I just can’t wait for the facts to come out,” he said. “I’m absolutely convinced I’ll be vindicated.”

Then he returned home, to that lush lawn and brick colonial, disappearing behind a closed door and drawn shades.