Cecil County's growing pains were becoming almost unmanageable by the winter of 2003. The pace of home construction was threatening the government's ability to provide basic services, such as water and sewer lines.

The county commissioners had what they thought was a solution: ask their state legislators for a bill establishing a 1 percent tax on real estate sales. It was a common practice, even on Maryland's tax-averse Eastern Shore.

But the Cecil commissioners ran into a major obstacle: state Sen. E.J. Pipkin (R-Queen Anne's). His opposition helped ensure that the measure never made it to the floor of the General Assembly. Nearby, in Caroline County, Pipkin lobbied against a bipartisan excise tax bill that would have paid for a new boiler in an aging high school. The bill was approved anyway. He said there were other ways to finance both efforts.

Pipkin's hard anti-tax line in Annapolis was a rough draft of the message he is bringing to voters in his U.S. Senate race against Democrat Barbara A. Mikulski: that the three-term incumbent has made a career of voting for higher taxes, more than 350 times. Mikulski says that number is a gross exaggeration.

"I believe that the money you make is yours to keep and that we have to take a little bit of it to service the government," Pipkin, 47, said in a recent interview. "Barbara Mikulski's view is that the money you make is the government's money, and she lets you keep a little bit of it."

Pipkin, the son of a Dundalk cafeteria worker and an electrician at Bethlehem Steel, made millions on Wall Street selling high-risk "junk bonds." He has poured more than $1 million of his own money into the race, triggering the so-called millionaire's amendment in the federal campaign finance law that allows Mikulski to solicit more funds from individual donors. Mikulski has raised more than $5 million. The campaign has become among the most expensive in Maryland history.

Pipkin's anti-tax theme is the most prominent of several basic messages he has tried to convey to voters this year.

He describes himself as a pro-environment, pro-military, anti-abortion Republican. Democrats like Mikulski have opposed federal judicial nominees, he says, because they think the jurists are "too religious."

Pipkin is waging his fight in a state where Democrats lead 2 to 1 among registered voters. Although a recent poll has him trailing Mikulski by as much as 20 percentage points, some Democrats think he has started to gain ground. The catalyst might have been a tough series of television ads launched last month that attack Mikulski for votes supporting taxes and opposing military spending. Through it all, Pipkin suggests that Mikulski is not who the voters think she is, but is a free-spending liberal who doesn't have their concerns at heart.

"Who knew?" the ads say.

Mikulski has fired back, asserting that Pipkin used procedural votes and Republican-sponsored "poison pill" amendments to distort her voting record on taxes. She describes his platform as "radical, right-wing kind of accusations" and "a cookie-cutter campaign right out of the Republican playbook."

The final results will be studied closely by elected officials in both parties who want to analyze changes in Maryland's political landscape since Republican Gov. Robert L. Ehrlich Jr.'s election in 2002. A stronger-than-expected showing by Pipkin would buoy Republican hopes that momentum from Ehrlich's upset win over Democratic Lt. Gov. Kathleen Kennedy Townsend can be carried into 2006.

Maryland Senate President Thomas V. Mike Miller Jr. (D-Calvert), who campaigned against Pipkin two years ago in his successful bid to unseat state Sen. Walter Baker, said Pipkin is a formidable foe. "He is a very bright person. He has his own money, his own ideas, and he got there without help from anybody," Miller said.

"I have told the Mikulski folks not to take him for granted. He will spend a lot of money and work tirelessly. He is going to get a very big vote."

Red Flag in Front of a Bull

Friends say politics was always in the back of Pipkin's mind, even as he grew wealthy on Wall Street in the boom years of the 1980s, where he traded so-called junk bonds. While they were often used as an instrument of debt to finance corporate takeovers, Pipkin says he sold only to insurance companies, pension managers and mutual funds.

Patrick Welsh, a former Baltimore County state senator who campaigned with Pipkin at his side 26 years ago, said public life clearly intrigued the young Roanoke College graduate. He had quit a Baltimore brokerage firm to help Welsh.

"He talked of his desire to go to Wall Street, and then he said, 'Maybe I would come back and go into politics.' That was the first inkling I had," Welsh said.

Pipkin put the notion on hold for almost 20 years, first at the University of Virginia's business school, which he says was a "boot camp" for the world that awaited him, then in New York, where he worked for brokerage firms such as Donaldson Lufkin and Jenrette, Lehman Brothers and Merrill Lynch.

Along the way, he was married, divorced and married again, starting a family with his wife Alisa, whom he met in New York. The couple has three children, including a 10-year-old daughter who is a championship figure skater.

He also became a Republican. Pipkin grew up in a Democratic household but said he left the party in 1992, when he attended the Democratic National Convention in New York. Although the nominee, Bill Clinton, was running on a centrist platform that rankled party liberals, Pipkin nonetheless decided that the Democrats had drifted too far to the left.

He left Wall Street in 1999 at age 42 and settled with his family into an 18-acre estate on Kent Island that he had bought originally as a weekend getaway.

Friends say he kept in touch with the old neighborhood, making frequent trips home to go to Orioles games in Baltimore and to visit his parents.

Just before he returned full time to Maryland, Pipkin had learned of a plan by Gov. Parris N. Glendening's administration to dump the spoils from dredging Baltimore's harbor into the Chesapeake Bay, not far from his bayfront home.

Pipkin organized and financed a campaign to stop the project. Welsh recalls one meeting when port officials belittled the citizen activists, saying they would fizzle out.

"That was like putting the red flag in front of the bull," Welsh said.

Three years later, the proposal was dead. Pipkin's efforts had helped to produce legislation that banned dumping in the bay.

And Pipkin had gained something else: credibility with environmental activists and a politically bankable name on the Eastern Shore.

'That's an F'

Pipkin won the fight, but he harbored resentment. His own state senator, Walter Baker, had voted against the open bay dumping bill.

"That's when I decided to run for state Senate," he recalled. Pipkin put together a coalition of environmentalists and local Republicans eager to dislodge Baker, 75, an Elkton Democrat who had held the seat for more than 20 years.

"I was given absolutely no chance to win that race," Pipkin recalled.

At 6-foot-2, the former college lacrosse player struck an imposing figure on the campaign trail. Pipkin says he knocked on 10,000 doors, and stood in traffic waving to voters and holding signs. He also spent about $600,000 of his own money, an unprecedented amount for a state Senate seat that pays $37,500.

Late in the race, as Democrats realized that Baker might actually lose, Miller and others began to mobilize. Pipkin won by about 24 percentage points.

"He is a pretty tenacious fighter, definitely laser focused," said Susan Brown, executive director of the Maryland branch of the League of Conservation Voters, who got to know Pipkin during the fight against open dumping in the bay.

Pipkin was the only one of the Eastern Shore's four state senators who didn't have a long history in local politics. He joined the Finance Committee and dug in to learn the ways of the General Assembly.

Although he enjoyed support from environmentalists in his campaign, his overall voting record in the Senate has not been that friendly to their cause. He scored a 53 out of 100 on the League of Conservation Voters' annual report card -- lower than most Democrats and some Republicans. "Where I come from, that's an F," said state Sen. Brian E. Frosh, a Montgomery County Democrat who routinely scores 100 percent on environmental scorecards.

The major environmental groups have endorsed Mikulski, something that Pipkin says disappoints him but doesn't surprise him. U.S. Rep. Wayne T. Gilchrest (R) recently wrote a letter on Pipkin's behalf, strongly suggesting that Pipkin's credentials were far more pro-environment than Mikulski's, particularly during the fight over open bay dumping.

Brown, of the Maryland branch of the League of Conservation Voters, also praised Pipkin for helping the group with its agenda in Annapolis. She cited his efforts in 2003 to try to broker a deal in which Ehrlich would have withdrawn his nomination of Lynn Buhl to head the state's environmental agency. Buhl's background, which included 10 years as an attorney for the auto maker now known as Daimler-Chrysler, made her unacceptable to the environmental camp.

The nomination was defeated, and Pipkin voted for her in the end, which Brown said she understood. "That wasn't an easy vote for him. You don't, out of the box, want to disagree with your governor on something like this."

This year, Pipkin focused on electric utility deregulation, holding a hearing that brought out utility companies in force. Pipkin was worried that rates would rise with deregulation, and Senate Minority Leader J. Lowell Stoltzfus believes his hearing helped keep them down.

"Had he not put the spotlight on it, the whole state of Maryland would have paid more," he said.

Some 'Political Advice'

Pipkin seems to thrive on talk. As he winds down from busy campaign days, he often gets on the phone with friends and supporters. These calls frequently come after 11 p.m.

"He'll be waking me up, asking me for political advice," Welsh said. "Sometimes it is, 'Please tell me if you think I am crazy.' I'm a sounding board."

State Republicans are pleased by the race Pipkin has run. Carol Hirschburg, a GOP consultant not involved in Pipkin's campaign, said his money and his energy will help the party in the state, no matter what the outcome on Nov. 2

Metro researcher Bobbye Pratt contributed to this report.

A profile of Sen. Barbara A. Mikulski is available at www.washingtonpost.com/metro.

Sen. E.J. Pipkin says, "I believe that the money you make is yours to keep and that we have to take a little bit of it to service the government."