George W. Bush campaigns for Jeb Bush in South Carolina

NORTH CHARLESTON, S.C. — More than seven years after he left office, President George W. Bush returned to the campaign trail Monday to defend his legacy and try to help his struggling younger brother, Jeb Bush, the former Florida governor who wants to extend the family dynasty in the White House.

George W. Bush reappeared at a time when his legacy, which had been improving, came under assault from within the Republican Party — chiefly by Donald Trump, who questioned the former president’s decision-making ahead of the Sept. 11, 2001, terrorist attacks and again in sending the U.S. to war in Iraq.

With Mr. Trump posing a threat to both Bushes, the family felt it was time to confront him with the former president himself.

“These are tough times, and I understand that Americans are angry and frustrated. But we do not need someone in the Oval Office who mirrors and inflames our anger and frustration,” the former president said, speaking to a half-filled exhibit hall. “We need someone who can fix the problems that cause our anger and frustration, and that’s Jeb Bush.”

The problem for Jeb Bush, however, is that much of the anger within the Republican Party is aimed at his father and brother, the past two Republican presidents, who many of the party’s voters say squandered the legacy of former President Ronald Reagan.

George H.W. Bush, who ran as a third Reagan term, broke his “no new taxes” pledge, and George W. Bush, while following through on his own tax cuts plan, led the U.S. into two wars that still rage more than a decade later, attempted to legalize most illegal immigrants and expanded government. Indeed, the size of the federal civilian agency workforce grew 17 percent under George W. Bush — more than the 10 percent under President Obama.

Jeb Bush’s run for the White House — and his brother’s return to the campaign trail — revive many of those debates.

“The GOP is a house divided against itself,” said Craig Shirley, a presidential history and biographer of Reagan, whose rise and eight years in office continue to enchant party members, who measure all other Republican candidates and presidents against him.

That divide plays out today — in the nine Republican presidential debates, Reagan’s name has been mentioned by the candidates 75 times. George W. Bush has been mentioned 26.

Mr. Shirley said the Bushes have been the chief alternative to Reaganism for the past four decades.

“During the 1980 campaign, there were many ideological and cultural issues dividing [George H.W.] Bush and Reagan. Bush was once asked if he was a liberal, a moderate or a conservative and he derisively said, ’Labels are for cans.’ Reagan of course would have said he was a conservative and then given an excellent lecture on American individualism,” Mr. Shirley said.

Indeed, George W. Bush repeated the “labels” line in his speech Monday night and said he embraced the “establishment” label if that was what it meant to be president.

Jeb Bush entered this year’s race as the Republican front-runner in a crowded and chaotic field, vowing to be tough on terrorists and to pursue legalization of illegal immigrants — and raising huge amounts of money in campaign donations from the Bush family network.

But Mr. Trump, who announced his campaign in June with a vow to deport illegal immigrants, quickly unseated Jeb Bush with a devastating critique of the former governor as too “low energy” to be president.

Mr. Trump denied Monday that there’s “bad blood” between him and the Bush family, but said he felt an obligation to fire back after Jeb Bush changed his campaign strategy to focus on trying to stand up to Mr. Trump.

Brent F. Nelsen, a political scientist at Furman University, said it was no surprise that the Bushes deployed the former president in the southeastern part of South Carolina, where establishment-minded Republicans are more plentiful. The northwestern part of the state trends more evangelical and tea party-friendly.

In this primary, those voters don’t overlap, meaning the two aren’t fighting for the same people right now.

“Their bringing of George W. to South Carolina indicates to me that Jeb Bush knows that he is not going to capture the Trump people or the Cruz people. He is absolutely focused on being the one establishment candidate that gets a ticket out of South Carolina — that’s a competition between Kasich, Rubio and Bush,” he said.

Whatever the anger at George W. Bush within Republican circles, it was generally contained to questions over his spending and war decisions. A frequent mantra for Republican voters was that the former president, while exploring an adventurous foreign policy, kept the homeland safe in the years after the Sept. 11, 2001, attacks.

But Mr. Trump has challenged even that orthodoxy, questioning how the former president can be said to have kept the country safe when the worst foreign attack on U.S. soil was perpetrated on his watch.

“I’ve heard for years that he kept the country safe after 9/11. What about during 9/11? I was there, I lost a lot of friends that were killed in that building,” Mr. Trump said.

Marc Thiessen, who was a speechwriter for George W. Bush, wrote in The Washington Post on Monday that Mr. Trump has become “a 9/11 ’truther’” who has gone even beyond House Minority Leader Nancy Pelosi, California Democrat. Mr. Theissen wrote that Mr. Trump went even further by claiming the CIA gave George W. Bush “advance notice” of the attacks, but the president didn’t act.

“This is the realm of conspiracy theory. In Republican circles, it is heresy,” he said.

Mr. Nelsen, who was in the debate audience Saturday when Mr. Trump began his attack about 9/11, said that with this, coupled with his dismissal of Sen. Lindsey Graham, the state’s senior Republican senator and a former presidential hopeful, it seemed Mr. Trump was trying to strike a blow at the heart of the Republican establishment.

“To the extent that he is calculating, he has decided that he has to run against the Republican elites — all of them, with the exception perhaps of Reagan,” Mr. Nelsen said. “To say that George Bush did not keep America safe, which has been a Democratic charge for a long time, but coming out of a Republican candidate — and a leading Republican candidate — has been heresy up to this point. But I don’t think it’s going to hurt him because he is all about bringing down the Republican elites.”

That battle between the insurgents and the elites has played out in Congress over the past six years, with leaders repeatedly running into trouble as they tried to broker compromises with Democrats that angered conservative leaders.

“There is a great deal of tension still remaining. The grass roots thinks they are Reaganites, and the elites think they are Bushies,” said Mr. Shirley. “In reality, they have very little in common. Reaganism is the expression of American conservatism, and Bushism is the expression of European conservative. With Reaganism, it is the belief that power flows upward from the citizenry to the institutions. With Bushism, it is the belief that power flows downward from institutions to the individual.”