Sen. Mitch McConnell was full of tough talk and bluster when it came to attacking the Obama administration and the current nuclear negotiations with Iran, but when it came to some trash talking from his fellow Republican senator, Ted Cruz (who attacked McConnell in his new book he's having trouble selling) old McTurtle retreated straight back into his shell.

Here he is on this weekend's Fox News Sunday running scared from Cruz:

BAIER: What do you make of -- what do you make of Donald Trump's success in the polls?

MCCONNELL: Look, I’m not going to get into all of the presidential candidates. We've got a bunch of ‘em. At the end of the day, I think we're going to have a candidate who can win.

BAIER: Here's a senator -- also who happens to be a candidate -- focus of criticism you are in his new book, "A Time for Truth." Texas Senator Ted Cruz, he accuses you and Senate leadership, of trying to dry up his fundraising, planned hit pieces in the press, end up hurting him. He says you said one thing publicly, another privately about the debt ceiling. He accuses you of capitulating to Democrats, to avoid bad headlines, says that, essentially, you’ve been lying. Not a great portrayal.

MCCONNELL: Look, I’m not going to take the bait and get into a discussion about the presidential campaign. We've got four senators running for president. A whole lot of other people as well. I think they can all do that without my assistance.

BAIER: So, can a candidate who calls you and other Republicans part of the Washington cartel win the nomination?

MCCONNELL: Well, look, it's a free country. These candidates can say anything they want to.

BAIER: Senator, thanks for your time.

MCCONNELL: Thank you.