Five days after he announced his candidacy for governor of Virginia, Republican Ken Cuccinelli II showed a side of himself seemingly at odds with his reputation as a tough law-and-order conservative.

The Virginia attorney general stood proudly at a news conference in late 2011 announcing the exoneration of a Richmond man who had spent 27 years in prison after being falsely convicted of rape. Cuccinelli had personally championed the man’s innocence, a sign of the broad evolution in Cuccinelli’s views on crime and punishment that would also lead him to argue that a frugal government should be more discerning about whom it puts behind bars.

“There is an expectation that the generic Republican position is tough on crime,” Cuccinelli said in an interview Thursday. “But even that has budget limits, particularly on the prison side.’’

Two decades after Republican George Allen charged into the Virginia governorship by vowing to eliminate parole for violent offenders, a rhetorical shift among the state’s leading conservatives reflects changing attitudes toward criminal justice nationwide.

U.S. Attorney General Eric H. Holder Jr. underscored the new dynamic last week when he announced reforms aimed at reducing sentences for some low-level offenders and slowing massive growth in the nation’s prison population. Republicans, who have targeted Holder on other issues, were generally supportive. The attorney general urged passage of legislation that has been introduced in Congress with bipartisan support that would give ­judges more discretion in applying stiff sentences to some drug crimes.

Violent crime has fallen, along with public concern over it as a major problem.

One person who discussed the plans with Holder said that the Obama administration felt like the political terrain was safe to make those kinds of policy ­changes because of the “conservative cover.’’ The person spoke on the condition of anonymity because the discussion was private.

Amid fiscal problems caused in part by massive prison populations and research showing that mass incarceration causes social harm, some leading conservatives have been pushing for reforms.

A generation ago, Republicans savaged Democrats as soft on crime, until former President Bill Clinton and others joined the GOP in a crackdown that continued even as the nation’s violent crime rate plummeted to historic lows.

“This is a fundamental shift in how we see criminal justice,’’ said David A. Harris, a University of Pittsburgh professor who studies crime and police. “There is a growing awareness of the fiscal and social costs of our great experiment in mass incarceration, and the balance has shifted from trying to look unrelentingly tough to asking what works best.’’

In a 1994 Gallup poll, 52 percent of Americans called crime the nation’s most pressing problem. Last month, that number was 2 percent. Other surveys show that fewer Americans support mandatory prison terms for offenders than in the mid-1990s, and fewer believe courts are too lenient with criminals.

During the same period, the nation’s violent crime rate has fallen nearly by half, according to FBI data. Yet the federal prison population has grown by about 800 percent since 1980.

More than half of the states have responded to the new landscape by enacting sentencing and other reforms since 2007, according to the Pew Charitable Trusts, which works with states and has tracked the changes in blue and red areas of the country. California, a reliably Democratic state, last year modified its “three strikes” sentencing law, which called for decades-long prison terms after even a minor third felony conviction. Republican-led Georgia recently relaxed its “mandatory minimum” sentencing laws, lowered penalties for some drug crimes and created substance abuse treatment programs for inmates.

Virginia, where the violent crime rate has fallen 45 percent since 1994, has not embraced such far-reaching changes. It has executed more people than any state except Texas since the death penalty was reinstated in 1976.

Yet even the commonwealth’s toughest law-and-order Republicans have moderated their positions on some crime issues and advocated for defendants’ rights. Gov. Robert F. McDonnell (R), a former prosecutor, this year reduced the time it takes nonviolent felons to regain their voting rights, drawing praise from the NAACP.

McDonnell announced his decision a day after a committee set up by Cuccinelli reported that the governor could do more to streamline the procedures.

McDonnell had long supported the principle of restoring voting rights. Cuccinelli voted against several such measures when he was in the Virginia Senate. As recently as 2009, he called the move “a horrible, horrible idea.’’

But Cuccinelli said his religious views as a Catholic helped fuel a recent change of heart. “Honestly, there’s an element — and there’s always been an element for me — in redemption, of wanting to see re-integration,” he said.

Democrat Terry McAuliffe, who is running against Cuccinelli for governor, said in a statement that Cuccinelli’s shift is “an election-year conversion.’’

The get-tough consensus

The campaign against crime that flooded prisons in Virginia and nationwide began as a re­action to urban riots, drug use and other perceived excesses of the 1960s and was fostered by fear of crime and opposition to pro-defendant court rulings, experts said. Politicians such as presidents Richard M. Nixon and Ronald Reagan ran in part on “law-and-order” platforms, and the crackdown was fully joined after Reagan was elected to the White House in 1980.

His administration declared war on drugs, and Congress, with bipartisan support, passed laws that established tough mandatory minimum sentences for marijuana and other drugs, especially crack cocaine. Republicans pilloried Democrats as soft on crime, particularly Massachusetts Gov. Michael S. Dukakis, the party’s 1988 presidential nominee, but both parties supported anti-crime measures.

“It was motherhood and apple pie to be tough on crime,’’ said Victoria Toensing, a Washington lawyer who was a senior Justice Department official in the late 1980s.

The anti-crime wave peaked in 1994, said Michael C. Campbell, a professor of criminology and criminal justice at the University of Missouri at St. Louis. That year, California passed its three-strikes law, resulting in sentences that critics said were excessive. One three-time felon, for example, was sentenced to 25 years-to-life in prison for stealing a single slice of pizza. Still, 20 other states would pass variants of the law by 2000.

Congress also passed a 1994 crime bill that funded prison expansions and required states that received the federal money to pass laws ensuring that violent offenders served at least 85 percent of their sentences.

“It was symbolic of the broader mood in the country,’’ Campbell said.

Allen’s campaign in Va.

In Virginia, 1994 saw the arrival of Allen in the governor’s mansion. The gubernatorial campaign had fit the prevailing mood. Democrat Mary Sue Terry, who stepped down as state attorney general to run in the election, battled with Allen over who would be tougher on crime. She promised to sharply limit parole for violent offenders. He vowed to eliminate it entirely for murderers, rapists and others.

“Bill Clinton’s campaign said during the election last year, ‘It’s the economy, stupid,’ ” Allen told the Virginia Sheriffs Association in 1993. “Well, this year, the issue is violent crime, and I say to my opponent, ‘It’s liberal parole laws, Mary Sue!’ ”

Less than a year after his victory, Allen achieved his aim: The Democratic-controlled state legislature voted to end parole. In 1995, Virginia also became one of numerous states to adopt so-called truth in sentencing, which required a violent offender to serve most of his or her sentence.

“Our focus was murderers, armed robbers, people who broke into other people’s homes, rapists, pedophiles,’’ Allen said in an interview Thursday. “That’s where the concern of Virginians was, and that’s where my concern was. I think Virginians are safer for it, and I can’t imagine Virginians saying they want to get back to that revolving-door approach.”

Indeed, in many ways the Virginia of today remains the same. The General Assembly, with bipartisan support, continues to pass laws that rachet up sentences for a variety of crimes. For the past several years, it has rejected proposals to change laws under which, for instance, a shoplifter who steals as little as $200 could face a felony conviction.

Del. Scott A. Surovell (D-Mount Vernon) said he sees “zero evidence” that the nationwide reform movement is gaining traction in the Virginia legislature.

Yet some prominent conservatives have shifted on criminal justice issues, among them Cuccinelli, who said he is concerned about the state’s average operating cost of $25,000 each year to house an inmate.

“When you’re going to spend $25,000 or $35,000 to keep someone out of society, you have to have a darn good reason for it,’’ said Cuccinelli, who has also warned in recent years against “felony creep” — harsh penalties for minor offenses — and expressed a willingness to examine the sentencing disparity between people convicted of using powdered cocaine and crack. Offenders who used crack — often minorities — have received much harsher jail terms.

In one prominent case, Cuccinelli, as the state’s top prosecutor, went so far as to argue the case of a defendant: Thomas Haynesworth, who had been mistakenly identified by a rape victim. He served 27 years in prison for a string of rapes and assaults before being released in 2011 after DNA evidence cleared him in two cases.

Cuccinelli personally took up Haynesworth’s case, arguing that a Virginia appeals court should declare him innocent even though there was no DNA to test in two other cases in which he had been convicted. He even gave Haynesworth a clerical job in the attorney general’s office.

In December 2011, the court issued a “writ of actual innocence,” a first in Virginia for a rape case that lacked the certainty of DNA evidence. As Haynesworth hailed the move at a news conference, the attorney general stood with him.

But Cuccinelli, who, unlike Allen in 1993, has not made crime a major issue in his campaign for governor, rejected any suggestion that Virginia has shifted away from its traditional posture. “I wouldn’t concede that anything we’re doing is soft on crime,’’ he said. “I think it’s more of a question of, ‘What works?’ ”

Scott Clement contributed to this report.