By Richard S. Dunham, Washington bureau

WASHINGTON — The president took a pummeling at the last Republican presidential debate. But the GOP candidates weren’t sniping at Barack Obama. They were criticizing the president’s Republican predecessor, George W. Bush.

Rick Santorum blasted his bailouts of the financial industry and domestic automobile companies. Mitt Romney chided him for failing to secure the U.S.-Mexico border. Newt Gingrich noted his unsuccessful effort to reform the U.S. immigration system. And Ron Paul attacked his involvement in Afghanistan and Iraq.

Bush, who retreated from national politics four years ago when he returned to Texas following two terms in the White House, is back in the political spotlight — but the glare is harsh.

“It’s just a very odd time,” said Margaret Spellings, Bush’s former education secretary. “George Bush ran as a different kind of Republican. (Now) we’re seeing a return to Republican orthodoxy prior to that point.”

NBC News senior political editor Mark Murray recently compared Bush’s role in the GOP presidential drama to the villainous Voldemort from the Harry Potter series: “He Who Must Not Be Named.”

Wooing the right

For most of the GOP primary race, Bush was a nonperson, rarely mentioned but rarely attacked — except for Texan Ron Paul’s lonely lectures about U.S. military intervention, torture of prisoners and American civil liberties violations.

That has changed in recent weeks as Republicans have competed aggressively for the backing of the most conservative primary and caucus voters. To woo those hard-right voters, they’ve bashed Bush as a big-spending, big-government, entitlement-adding, weak-on-illegal-immigration, soft-on-Iran failure.

His foreign policy legacy, from his war on terrorism to U.S. involvement in Afghanistan and Iraq, has been attacked incessantly by Paul, the Texas congressman who embraces a noninterventionist philosophy.

Santorum, meanwhile, notes with pride that he sponsored legislation requiring U.S. sanctions on Iran for pursuing a nuclear program when “President Bush opposed me for two years.”

Programs attacked

Bush’s two proudest domestic policy accomplishments — his No Child Left Behind education reforms and Medicare drug benefit for elderly Americans — have been pilloried as government overreach and costly expansions of power.

At the Feb. 22 Republican debate, Santorum apologized for supporting No Child Left Behind, admitting that “I took one for the team leader” despite the fact “it was against the principles I believed in.”

All of the Republicans now promise to repeal Bush’s education overhaul along with Obama’s health care reforms. And his immigration enforcement record has been blasted both by Romney and Texas Gov. Rick Perry, whose presidential campaign ended in January. Romney and Paul have lambasted Bush’s administration for running up record deficits — since surpassed by Obama.

Ironically, two of Romney’s top economic advisers, R. Glenn Hubbard, of Columbia University, and Gregory Mankiw, of Harvard, served as chairmen of Bush’s White House Council of Economic Advisers. Neither responded to interview requests.

Republican political professionals say the attacks on Bush reflect the seismic shifts in the Republican primary electorate over the past decade.

“The political ground has shifted from beneath us and has moved to the right,” said GOP consultant Matt Mackowiak. “What was accepted Republican philosophy in the 2001 to 2006 time frame is now not viewed as conservative and is almost apostasy.”

Mackowiak said the GOP candidates feel free to bash Bush because he remains unpopular in national surveys and has taken a vow to stay out of the 2012 primary battles.

“Bush 43 is not going to punch back, so it costs you very little” to criticize him, Mackowiak noted.

Rising to defense

With the former president declining comment, other Texas Republicans are coming to his defense.

Rep. Pete Olson on Thursday issued a press release headlined “thank you President Bush” and highlighting his fellow Texan’s commitment to energy exploration.

“It was President Bush who ended the moratorium on offshore drilling and expanded federal leasing,” the Sugar Land Republican declared. “So thank you President Bush for helping America to reduce our reliance on foreign oil.”

Spellings, a close Bush confidante and a key player in his education policy, says she is puzzled by Republican criticism of Bush’s accomplishments. She says No Child Left Behind figures “very prominently” in Bush’s legacy and “we’re not trying to run and hide,” despite GOP campaign criticism and House Republican attempts to repeal it.

Democrats are watching the Republican-on-Republican violence with bemusement.

“Only this field of Republican presidential contenders could make President Bush look like a moderate,” said Rebecca Acuña, deputy political director of the Texas Democratic Party. “The days of compassionate conservatism are long gone in the Republican Party.”

Sharanya Shankar of the Washington bureau contributed to this report.