Not only is this kind of name calling juvenile, the epithet "wacko birds" may be the most bizarre thing McCain has ever said.

In any case, the Arizona Senator has apologized.

Politico:

Sen. John McCain is apologizing for calling Sens. Rand Paul and Ted Cruz "wacko birds" and says he respects what his Senate colleagues stand for.

"[In] an interview I said that Sen. Cruz and Sen. Paul were 'wacko birds.' That was inappropriate and I apologize to them for saying that, and I respect them both. I respect what they stand for and what they believe in. They both made an impact out here in the United States Senate," McCain (R-Ariz.) said on Fox News on Friday.

cCain had previously told The Huffington Post earlier this month that Cruz (R-Texas), Paul (R-Ky.) and Rep. Justin Amash (R-Mich.) were "wacko birds" for their outspoken brand of politicking on the Hill. McCain has also criticized Paul for his nearly 13-hour filibuster that pressured President Barack Obama's administration to clarify its position on the use of domestic drones.

During his speech at the Conservative Political Action Conference on Thursday, Paul -- who is considering a 2016 presidential run -- seemingly alluded to McCain's criticisms.

"The GOP of old has grown stale and moss covered," Paul said during his CPAC speech. "I don't think we need to name names here, do we?"

Responding to that line on Fox News, McCain jokingly wiped his face, pretending to wipe off moss.

"I got to get that moss," McCain said, scratching his face and laughing after the clip was played. "Everyone is entitled to their views."

Fox News host Neil Cavuto asked McCain about the irony that McCain -- long considered a "maverick" in the Senate -- is now being criticized for being too old school.

"Life isn't fair, as you know Neil, but the important thing for me is to be in the arena and part of the debate and try to contribute to the future of the country and represent the people of Arizona," McCain said. "And when you're in the arena, as you know, you're going to take arrows, you're going to take hits and you're going to make mistakes. And I've made my share."