If anything gets Sen. John McCain’s blood boiling in Congress, it’s his fellow Republican lawmaker Ted Cruz.

McCain, the elder statesman of the Republican Party in the Senate, and someone with generally an even demeanor, has several times grown visibly annoyed by the Texas freshman.

The Arizona senator, who is 77, even called Cruz, who is 42, and Sen. Rand Paul, “wacko birds” earlier this year.

“They were elected,” McCain said back in March. “But I also think that when, you know, it’s always the wacko birds on right and left that get the media megaphone. I think it can be harmful if there is a belief among the American people that those people are reflective of the views of the majority of Republicans.”

Cruz infuriated McCain this week again when, during his 21-hour marathon speech aimed at killing President Obama’s Affordable Care Act, the Texan drew a parallel between accepting the health care program and appeasing Adolf Hitler, according to published reports.

“Look, we saw in Britain, Neville Chamberlain, who told the British people, ‘Accept the Nazis. Yes, they’ll dominate the continent of Europe but that’s not our problem,” Cruz said on the Senate floor on Wednesday. “’Let’s appease them. Why? Because it can’t be done. We can’t possibly stand against them.’”

The comparison between Nazi apologists and those who accept the Affordable Care Act drew a rebuke from McCain.

Comparing the so-called Obamacare to the Nazi threat, McCain said, "does a great disservice" to Americans who fought against the Nazis.

He also, in so many words, offered Cruz a lesson in democracy.

“We fought as hard as we could, in a fair and honest manner, and we lost,” McCain said after Cruz’s marathon speech on Wednesday. “And we lost, one of the reasons is because we were in the minority.And, in democracies, uh, almost always, the majority governs and passes legislation.”

Though McCain noted that while Republicans had the right to try to improve upon the president’s health care plan, “elections have consequences" and Republicans should "respect the outcome" of the 2012 election.

Cruz also has taken a polar opposite position from McCain on comprehensive immigration reform, which the Arizona lawmaker supports. McCain was part of the Senate’s bipartisan Gang of Eight, which drafted a bill that tightened enforcement and provided a pathway to legal status for many of the country’s estimated 11 million undocumented immigrants. Cruz has said he firmly opposes any kind of break for undocumented immigrants and will not support a measure that provides “amnesty.

McCain’s “wacko birds” comment immediately drew a reaction from Cruz, who mocked it.

“If standing for liberty and standing for the Constitution makes you a wacko bird, then count me a proud wacko bird,” Cruz said as he delivered the keynote address at the Conservative Political Action Conference in National Harbor, Md.

On Wednesday, Cruz said he has learned that defying party leaders is "survivable," adding, "Ultimately, it is liberating" and that his long evening involved "sometimes some pain, sometimes fatigue."

But he added, "You know what? There's far more pain in rolling over. ... Far more pain in not standing up for principle."

The Associated Press contributed to this report.

Follow us on twitter.com/foxnewslatino
Like us at facebook.com/foxnewslatino