WASHINGTON Establishment Republicans in Congress such as John McCain are openly scornful of him. Some Republican strategists say his crusade to destroy President Barack Obama's healthcare law has been a political disaster.
But at a gathering of conservatives and Tea Party faithful in Washington on Friday, Republican Senator Ted Cruz was unapologetic, defiant and received like a conquering hero.
As Republican leaders in Congress have abandoned a strategy to use a government shutdown and threat of default to dismantle Obama's healthcare overhaul - with polls showing it unpopular with voters - one thing was clear at the gathering of conservative activists: they believe the battle to kill Obamacare has only just begun.
Cruz, a freshman Texas lawmaker who made a 21-hour speech last month on the Senate floor decrying Obama's health law, has become the face of conservative opposition to the legislation.
To multiple standing ovations and cries of "tyranny" every time he mentioned Obama's name, Cruz told a big crowd of conservative Republicans at the Values Voter Summit that he knew exactly what he was doing, and battle had only just been joined.
America, he said, was just two years away from oblivion unless there was radical change. And at the heart of what was needed, he said, was "to stop that train wreck, that disaster, that nightmare that is Obamacare."
Cruz was frequently greeted with whoops of support and prolonged applause. He was also met with hecklers, whom he called "President Obama's paid political operatives." They were shouted down and removed.
Cruz said that after he spoke, he was going with fellow Republican senators to meet Obama in the White House.
"If I am not seen again please send a search and rescue team," Cruz said.
Speaking before Cruz was fellow conservative Republican Senator Mike Lee from Utah, who has partnered Cruz in the fight to dismantle the healthcare law.
"We make no apologies," Lee declared over the failed fight to block Obamacare. "We must stop it, we must defeat it, and we cannot accept it." Lee, too, was given a standing ovation.
Michelle Wiegand, 43, attending the conference with her two-year-old son Declan, said of Cruz and Lee's efforts to end Obamacare: "Even if nothing comes of it, they showed great political courage. That is rare in Washington. This is a law not supported by the majority of the American public."
With the Republican leadership now negotiating with Obama on a deal to lift the debt ceiling and reopen the government, some Republican strategists said Cruz's strategy had been a mistake all along.
"His battle is over," said Charlie Black, a veteran party strategist. "It was a bad idea. He was trying to do something that was impossible. There is a Democratic president and a Democratic Senate. He's new to Washington. Maybe he didn't know what was possible."
Senator McCain from Arizona, a former presidential candidate, and Representative Peter King from New York have been two of the most vocal opponents of Cruz's tactics, with McCain calling Cruz and his allies "wacko birds."
Cruz has also taken a hit in the polls. A Gallup poll released on Thursday found that he has gained significant name recognition, but the percentage of Americans with an unfavorable view of him has jumped to 36 percent from 18 percent in June.
Ford O'Connell, a Republican political adviser, said opposition to the healthcare law was justified, but Cruz's tactics were "completely wrong."
"Cruz has done a good job of bringing this to the attention of the American people - but the government shutdown has completely obstructed his message," Ford said.
"The key to successful political negotiating is to pull the right lever at the right time. Unfortunately for the Republican party, the Tea Party caucus is pulling the right lever at the wrong time."
(Reporting by Tim Reid; Editing by Karey Van Hall and Claudia Parsons)