Republican presidential candidate Sen. Ted Cruz of Texas gestures during a break in Tuesday's debate. (Robyn Beck/AFP/Getty Images)

Ted Cruz is a smooth political operator. Even his critics have to give him that. A former debate champion at Princeton, the Texas senator seldom gets tied in a rhetorical knot, not matter how tangled a situation might seem.

Recall the masterful way he talked around Stephen Colbert’s surprise mention of same-sex marriage during an appearance on “The Late Show” in September. Aware that his opposition to gay marriage is unpopular with the host — and apparently with the audience, based on audible reactions — Cruz quickly flipped the discussion into one about states’ rights to make their own marriage laws.

So it was borderline stunning to see Cruz squirm on Fox News Channel on Wednesday evening, when Bret Baier challenged the Republican presidential candidate’s assertion — made in Tuesday’s debate — that he has never supported allowing undocumented immigrants to obtain legal status.

Baier cited interviews and statements Cruz made on the Senate floor in 2013, when he was pushing an amendment to the so-called “Gang of Eight” immigration bill (Sen. Marco Rubio of Florida, another GOP White House hopeful, was in the gang) that laid out a path to citizenship for undocumented immigrants. Cruz wanted to take citizenship off the table but made clear at the time that he would be willing to grant some legal status.

As Baier pointed out, Cruz’s earlier statements don’t jibe with what he said on the debate stage in Las Vegas: “I've never supported legalization; I do not intend to support it.”

Baier played a tape of Cruz’s May 2013 testimony before the Senate Judiciary Committee, in which he said: “I don’t want immigration reform to fail; I want immigration reform to pass. And so I would urge people of good faith on both sides of the aisle, if the objective is to pass common-sense immigration reform that secures the borders, that improves legal immigration and that allows those here illegally to come out of the shadows, then we should look for areas of bipartisan agreement and compromise to come together.”

Cruz was clearly stuck. He tried to argue that his objective was to “defeat Marco Rubio’s amnesty” with his amendment. But Baier fired back with Cruz’s own words: “The problem, though, is that at the time you were telling people like Byron York with the Washington Examiner that this was not a poison pill. You told him, ‘My objective was not to kill immigration reform.’ You said you wanted it to pass at the time.”

Now, this might be a fluke. In fact, I’ll go so far as to say that Cruz will use the uncomfortable exchange with Baier to up his game going forward.

But it’s worth remembering that Cruz has enjoyed underdog status throughout the campaign, drafting off Donald Trump. While Trump still holds a large lead in national polls, Cruz is a real threat in Iowa and looks increasingly — to voters and the press — like a real contender for the GOP nomination.

That means he should expect to get more of the tough, front-runner treatment that he got from Baier on Wednesday. He’s never faced that kind of pressure before. We’ll see if he cracks -- and if others can emulate Baier's tough interview.