Republican presidential candidate Sen. Ted Cruz (R-Texas). (Carolyn Kaster/AP)

Ted Cruz has been branded a “wacko bird” by a Senate colleague and a “jackass” by the former speaker of the House. A GOP consultant labeled him a show horse, and a strategist for a rival presidential campaign called him the Mitt Romney of 2016 — the Republican no other Republican can stand.

“I just don’t like the guy,” former president George W. Bush, Cruz’s old boss, told supporters at a fundraiser for his brother Jeb Bush last month.

The list of GOP politicians and operatives willing to take open shots at Cruz has grown long: Sen. John McCain (Ariz.), Sen. Rand Paul (Ky.), former Arkansas governor Mike Huckabee, former House speaker John A. Boehner (Ohio), Sen. Lindsey O. Graham (S.C.), fellow Texas Sen. John Cornyn, Sen. John Thune (S.D.), former senator Tom Coburn (Okla.) — and on and on.

Cruz does not appear to be bothered. The senator and presidential candidate seems to relish the fact that so many fellow Republicans love to hate him. On the trail, the Texas Republican fondly recounts his skirmishes. His campaign blasts out fundraising e-mails quoting the critical words. When Boehner called Cruz a jackass, his campaign’s solicitation quoted him as saying, “I will wear it as a badge of honor because I refuse to join their club.” A super PAC supporting Cruz released a radio spot Tuesday boasting that Boehner referred to Cruz as a “a pain in the you-know-what.”

In other words, Cruz’s status as persona non grata has become part of his political persona: He uses the enmity of others to paint himself as an outsider, someone whose role taking on Washington prompted an ugly backlash from the establishment that he counts as a point of pride.

Look for him to relish the role at his next chance to get under his rivals’ skin — at a debate hosted by Fox Business Network in Milwaukee on Tuesday.

“I will acknowledge that when I’m in the Senate dining room I’ve sometimes wondered if I need a food taster,” Cruz said to laughs in Fort Dodge, Iowa, last month. He added: “If you ain’t never stood up to Washington, at any time in your life, you’re not gonna suddenly discover the courage to do so if you happen to land at 1600 Pennsylvania Avenue.”

Many of those who knock Cruz cite the same origins of their antipathy: Cruz is a grandstander, they say, who trashes fellow Republicans for his own gain. Once an admirer of John G. Roberts Jr., he now criticizes the chief justice — and Bush too, the president who appointed Roberts. He unsuccessfully tried to stop passage of a spending bill last year, forcing a series of weekend votes. He pointedly refused to endorse Cornyn in a primary race two years ago — a breach of Senate etiquette.

“There’s not a lot of love lost for the guy,” said Josh Holmes, a former chief of staff to Senate Majority Leader Mitch McConnell (Ky.). “And it’ s not what he’s trying to accomplish or what he says he’s trying to accomplish that bothers people,” Holmes added. “It’s that he’s consistently sacrificed the mutual goals of many for his personal enhancement.”

Karl Rove, a former senior adviser to Bush, sees Cruz as someone who conveniently takes aim at former allies “for political purposes.”

Rove said on Fox News recently that Bush soured on Cruz even though the younger Texan got his start on Bush’s 2000 campaign. It happened in part because Cruz faulted Bush for appointing Roberts to the top spot on the Supreme Court — and criticized his father, George H.W. Bush, for appointing since-retired justice David Souter.

The ex-president “thought it was a little opportunistic,” Rove said.

Cruz has vowed not to speak ill of any other Republicans running for the presidential nomination, but the trail has not been free of quarrels.

Paul, one of the first national figures to endorse Cruz for his Senate race but now a rival for the GOP presidential nomination, has waded into an increasingly bitter fight with Cruz. Both men proposed plans to cut funds for Planned Parenthood, and both failed, but Cruz described Paul’s as a “show vote.” In an interview with Fox News Radio, Paul attacked Cruz as a blunderer who’d “chosen to make this really personal and chosen to call people dishonest in leadership and call them names, which really goes against the decorum and also against the rules of the Senate.”

Huckabee, another rival for the nomination, spent days organizing a rally celebrating the liberation of Rowan County, Ky., Clerk Kim Davis, only to find that Cruz would be stopping by. Huckabee’s organization physically prevented Cruz from speaking onstage or to a scrum of reporters, which forced him to give impromptu remarks far from the media’s glare.

Cruz has also alienated many in Congress with his 2013 fight against the Affordable Care Act, which led to a government shutdown. He has spent much of his time in the Senate openly warring with both parties.

“He plays into the frustrations and passions of good people,” said Graham, another rival for the Republican presidential nomination, “and creates narratives that don’t exist at the expense of others. I don’t think that’s leadership. I think that’s demagoguery.”

That hasn’t always been Cruz’s style.

Long before he slammed the chief justice after rulings upholding the Affordable Care Act and legalizing same-sex marriage nationwide (Roberts dissented in that 5-to-4 decision), Cruz once emulated Roberts’s arguments and invited him to participate in the 2000 Florida recount.

And in “Thank You, President Bush,” a 2004 collection of essays, Cruz defended the president’s spending and education records. Comparing Bush to Lincoln, Cruz argued that critics failed to understand politics and needed to tone down such extreme rallying cries as one to abolish the Education Department. When voters hear that, Cruz wrote at the time, “a lot of voters just hear ‘abolish education’ and back away.”

Fast forward to 2015, when Cruz is campaigning to abolish the Education Department — and describing his days in the Bush orbit less happily. In his own memoir,“A Time for Truth,” Cruz wrote that he was cocky while working on the Bush campaign and overstepped his bounds.

“They really didn’t give a flip what some twenty-something kid thought might or might not be the right policy outcome,” he wrote. “As a consequence, I burned a fair number of bridges on the Bush campaign.”

Cruz also chronicled his Senate spats in the book, writing that the “driving force” in Washington on both sides of the aisle is “risk aversion.” Government is “corrupt,” he wrote, and telling the truth in Washington is a “radical act.” He recalled a lunch where he said he wouldn’t go forward with a leadership plan on the debt limit.

“In the two years I’ve been in the Senate, nothing I have said or done has engendered more venom and animosity from my fellow Republicans than the simple objection I made that afternoon,” he wrote.

More recently, Cruz has called McConnell a liar on the Senate floor, and he said on the floor and elsewhere that Republican leaders are “effective” Democrats who provide a rubber stamp for President Obama.

Some said Cruz makes a lot of noise in the Senate but gets little done.

“It’s a classic show-horse-
versus-workhorse dynamic,” said John Hart, former communications director for Coburn. “It’s putting his own political ambition ahead of the interests of the country, and I hope voters see through it.”

Cruz’s actions have at times attracted a backlash.

In September, McConnell went out of his way to deny Cruz the chance to shut down the government over the funding of Planned Parenthood, and Republican senators celebrated Cruz’s defeat.

In both July and September, senators denied Cruz a procedural courtesy granting him a roll-call vote, a rare rebuke illustrating his unpopularity among his colleagues.

“That is different than anything I’ve ever seen in my years here,” said McCain, a longtime nemesis.

Catherine Frazier, a Cruz spokeswoman, said the senator has “a record of effectiveness” in Congress and “shined a light” on the failures of the Republican majority.

“These people keep shooting arrows at him, trying to take him out, and he’s not going anywhere,” she said.

To some supporters, Cruz’s skirmishes make the candidate more attractive.

“He’s hated by the political establishment,” said Chart Westcott, a Dallas biotech investor and Cruz donor. “He’s got that original outsider status, and that’s what I love and has made him attractive to so many swaths of Americans.”

Despite his bomb-throwing persona, Cruz is often a genial presence in person and on the campaign trail, cracking jokes, doing impressions and telling stories about his young daughters.

Rob Marks, a friend from Cruz’s time at Princeton University, said he understands why some people might take the firmness in beliefs for arrogance.

“A lot of people did not like him, I think that’s a fair statement. He got in controversies. He didn’t shy away from them,” Marks said of their years debating at Princeton University.

But Marks and another friend, David Panton, describe Cruz as fiercely loyal. Panton’s father was diagnosed with terminal cancer and Panton thought Cruz didn’t know; the senator and his wife found out and sent a spray of yellow carnations to the hospital room. Cruz called Panton shortly after the flowers arrived earlier this year to wish Panton a happy birthday and was one of the last people to speak to Panton’s father before he died.

Panton said he asked Cruz recently how he stands the constant criticism and deflects the barbs.

“I said, ‘Ted, how do you deal with this?’ ” Panton said. “He said, ‘I believe in what I’m doing.’ Ted definitely has an incredibly thick skin.”

Abby Livingston and Kelsey Snell contributed to this report.