I had a twinge of nostalgia watching George W. Bush campaign for his little brother in South Carolina on Monday night.

He was earthy. He recalled a previous visit to a South Carolina breakfast spot, where an animal-rights demonstrator dressed as a pig interrupted Bush’s meal by dumping a “steaming pile of manure” in the parking lot to block his exit.

Bush was corny. He spoke about how, in his presidential “afterlife,” he has become a tree farmer — “gives me a chance to practice my stump speech.”

He also was self-deprecating. “I’ve written two books, which has surprised a lot of people, particularly up east who didn’t think I could read, much less write,” he said.

But mostly, W’s cameo in the 2016 campaign served as a reminder that, not too long ago, conservative politics wasn’t so beastly. Bush, wading into the manure pile that is the 2016 Republican primary fight, was pleasant, civil and decent.

“If serving as president of the United States makes me a part of the so-called establishment, I proudly carry that label,” he said, responding to the “outsider” fury fueled by Donald Trump and Ted Cruz. “There seems to be a lot of name-calling going on, but I want to remind you what our good dad told me one time. Labels are for soup cans. The presidency is a serious job that requires sound judgment and good ideas.”

Without mentioning Trump’s name, Bush belittled the bombastic billionaire. “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,” Bush said.

Then he made his best case for Jeb: “Strength is not empty rhetoric. It is not bluster. It is not theatrics. Real strength, strength of purpose, comes from integrity and character. And in my experience, the strongest person usually isn’t the loudest one in the room.”

This isn’t to idealize Bush, who did his share to coarsen political discourse: impugning his opponents’ patriotism, exaggerating intelligence to lead the country to war, and building the false case that Iraq was behind the 9/11 attacks. But even Karl Rove’s underhandedness seems almost quaint compared with today’s brutality.

The party isn’t necessarily more conservative; Trump is less a conservative than a purveyor of insults, nationalism and conspiracy theories. Trump and Cruz are making the Republican Party into a rage-filled movement, as the dueling demagogues chew up opponents and each other. Some excerpts from Saturday night’s debate:

“They lied!”

“He lies.”

“This guy lied.”

“That’s a lot of lies.”

“Why do you lie?”

“You are the single biggest liar.”

“It’s a disgrace and an embarrassment.”

“Give me a break.”

“This country is dying.”

“I don’t know how he knows what I said on Univision because he doesn’t speak Spanish.”

“He is so weak on illegal immigration it’s laughable.”

“You want to talk about weakness? It’s weak to disparage women. It’s weak to denigrate the disabled.”

“He said he would take his pants off and moon everybody.”

“He called him pathological and compared him to a child molester.”

“Nasty guy.”

Trump took particular aim at the 43rd president, saying: “They lied. They said there were weapons of mass destruction. There were none, and they knew there were none.”

At a news conference Monday — the same event where Trump repeatedly called Cruz “unstable” and said he would file a lawsuit to disqualify Cruz from the presidency because of his Canadian birth — Trump flirted with the “truther” accusation that Bush had advance knowledge of the 9/11 attacks. “They knew some bad things were going to happen,” Trump alleged. “They could have stopped it.”

Bush responded mildly to Trump’s provocations, recalling the child’s face he looked into when he first learned of the 9/11 attacks. The former president answered the Bible-bungling Trump with a passage on hypocrisy from Matthew about removing the speck from your brother’s eye when there is a log in your own.

“We need someone who can take a positive message across the entire country, someone who can inspire and appeal to people from all walks of life, not just one party or one class of people,” he said. Jeb “will rise above the petty name-calling.”

Maybe, or maybe W’s appearance will serve only to remind voters of Jeb’s inferior political skills. Either way, the 43rd president’s re-emergence offered Republicans a chance to reflect on how Bush’s party of conservatism so quickly became Trump’s party of rage.

Dana Milbank is a columnist for The Washington Post. His email address is danamilbank@washpost.com.