Ted Cruz vs. John McCain: This time, it's about Hitler.

Sen. John McCain went after the freshman senator for a reference to appeasement of Adolf Hitler that Sen. Ted Cruz made during his epic 21-hour talkathon against Obamacare on the Senate floor.

Ted Cruz and John McCain are both Republican senators, but they’re far from collegial. There is something about freshman Cruz’s aggressive style of politics that does not sit well with McCain, who’s been a member of the Senate club for some 26 years.

It was Senator McCain, angry at Senator Cruz’s battering of ex-Sen. Chuck Hagel during Hagel’s confirmation hearing to be secretary of Defense, who labeled Cruz and his allies “wacko birds.” A new GQ profile of Cruz quotes an anonymous McCain adviser as saying that the Arizona senator “hates” the Texas newcomer.

“He’s just offended by his style,” this aide tells GQ.

Now the angry veteran of GOP politics is after Cruz once again. This time, it’s about a reference to appeasement of Adolf Hitler that Cruz made during his epic 21-hour fili-talkathon against Obamacare on the Senate floor.

This came during a long section in which Cruz was talking about times in history when “pundits” said things could not be done, but then they were.

For instance, during the Civil War, there “were a lot of voices who said the Union cannot be saved,” Cruz said, but it was.

Then came the Nazi part.

“If we go to the 1940s, Nazi Germany – look, we saw it in Britain. Neville Chamberlain told the British people: Accept the Nazis. Yes, they will dominate the continent of Europe, but that is not our problem. Let’s appease them. Why? Because it can’t be done. We cannot possibly stand against them,” Cruz said.

At this, McCain took umbrage. Why? Well, for one thing, umbrage and McCain are well acquainted. For another, it’s because this seems like a reference to the GOP Senate establishment, which disdained Cruz’s talkathon against Obamacare as a waste of time. Democrats control the Senate, in this view, and President Obama will veto anything that defunds his signature health law achievement.

“I resoundingly reject that allegation. That allegation, in my view, does a great disservice. I do not agree with that comparison. I think it’s wrong,” McCain said on the Senate floor shortly after Cruz’s speech ended.

McCain went on to say that Cruz had told him he was speaking only about talking heads, but McCain wasn’t buying it. “I find that a difference without a distinction. I find that something that I think I have to respond to,” McCain said.

So he continued responding, saying in essence that to compare the two situations was pretty objectionable, considering. Left unsaid was the obvious point that as a war veteran and former POW, whose grandfather commanded US naval air forces at Guadalcanal and whose father captained a World War II sub in the Pacific, McCain does not think comparisons between the legislative process and Hitler should be made too easily.

He did say that the voters had the chance to consider Obamacare in 2012 – and the GOP nominee lost.

“The people spoke: They spoke much to my dismay. But they spoke, and they reelected the president of the United States,” McCain said.

Given that McCain took to the floor shortly after Cruz left it, his words were something of a purposeful slap in the face. Cruz’s conservative supporters replied in kind.

“Beltway barnacle McCain’s longevity is NOT admirable. It’s a bane,” tweeted right-leaning pundit Michelle Malkin.

Plus, McCain’s animosity is unlikely to weaken Cruz’s position in the GOP firmament, since McCain is the definition of Republican establishment and Cruz is a leader of the insurgent tea party wing of the GOP.

In fact, it’s possible McCain’s anger could actually strengthen Cruz, since it shows the Texas senator can get under the skin of someone whom the populist tea party wing considers a virtual Democrat.

“It’s fun for Dems when McCain lights into Cruz, but no Republican’s criticism does more to endear Cruz to the base,” tweeted Slate political analyst Dave Weigel.