Republican presidential candidate Sen. Ted Cruz (R-Tex.) in Sanbornville, N.H.  (AP Photo/John Minchillo)

With four days to go before the Iowa caucuses, Sen. Ted Cruz (R-Tex.) got a rare chance to act like the front-runner in the Republican race for president at Thursday night’s debate, hosted by Fox News.

It didn’t go all that well.

By Friday morning, he had earned a brutal headline in Iowa’s leading newspaper, the Des Moines Register, which stripped across its front page “Rough Night for Cruz."

Without Donald Trump to draw fire from the other candidates — Trump skipped the debate to boycott Fox News over a dispute about moderator Megyn Kelly — Cruz took incoming fire during the debate from numerous other candidates on immigration, his performance in the Senate and his positions on surveillance issues.

[In Trump vacuum, Cruz emerges as top target]

At one point he tried, and failed, to seize control of the debate from moderator Chris Wallace, drawing a rebuke from the Fox News anchor. And his attempts to poke fun at the absent Trump with rehearsed joke lines drew mixed reviews.

Polls had showed Cruz in the lead in Iowa, but in recent days they have indicated that he has been slipping in the state, with Trump regaining momentum. With its conservative and heavily evangelical voter base, Iowa is a must-win for the Texas senator, who has worked especially hard to organize pastors and religious voters.

The pile-on for Cruz continued into Friday morning, with opponents hitting him on morning news programs for changing his positions on a variety of issues even as he has campaigned as the most pure conservative in the race.

“When a person changes views time after time and is always moving with the political weather vane, when a person is a thermometer, not a thermostat, that person’s not a leader,” said former Arkansas governor Mike Huckabee on CNN. Huckabee, who wants to draw from the same evangelical base as Cruz, has been a particular critic.

On MSNBC, New Jersey Gov. Chris Christie said he thought Cruz “had a tough time explaining” his position on immigration during the debate. Christie lumped Cruz together with fellow Republican Sen. Marco Rubio (Fla.). During the debate, moderators played clips of both Cruz and Rubio showing that the two have shifted position on immigration. Rubio had called a path to citizenship “amnesty” during his campaign for the Senate in 2010 before joining a bipartisan group of senators who pushed immigration reform that included one. Cruz now says he was working to kill that bill, but in 2013 said he was pushing amendments to it in hopes it would pass.

“They showed video of Sen. Rubio and Sen. Cruz obviously having changed their positions on immigration, and neither one of them was willing to admit it,” Christie said. “That’s why people are so frustrated with Washington, D.C. No accountability, and they try to tell you that what we just saw and what we just heard wasn’t really true.”