It’s not exactly a secret that Sens. John McCain (R-AZ) and Rand Paul (R-KY) have had a rocky relationship. Angry over the Paul-led filibuster of CIA nominee John Brennan, McCain called the Senators who participated “wacko birds” and tried to dismiss their criticism of President Barack Obama’s drones program.

But with Paul seemingly planning a bid for the Republican presidential nomination in 2016, McCain told The New Republic, a left-of-center publication, that he would have a “tough choice” between former Secretary of State Hillary Clinton and Paul.

Asked whether or not Republican leadership has been “frozen” by Paul an Sen. Ted Cruz (R-TX), McCain, who was the Republican standard-bearer in 2008, went into a brief tirade about “isolationism” in the Republican Party, a frequent complaint and smear from neo-conservatives who have seen their power challenged.

“I am not sure if it has been frozen, but certainly there is an element in the party that has been there prior to [World War II], the isolationist, America-Firsters. Prior to World War I, it was Western senators, and then Henry Ford and Charles Lindbergh, and then Taft versus Eisenhower,” said McCain, according to the transcript. “Even Reagan—Reagan’s presidency was perfect without ever a problem [said sarcastically]—there was an isolationist wing that fought against Reagan. And now the bad economy has exacerbated what has always been out there.”

“When Hillary Clinton versus Rand Paul occurs in 2016, I guess you are going to have to decide who to vote for, huh?” asked Isaac Chotiner of The New Republic, to which McCain replied laughingly, “It’s gonna be a tough choice.”

“Let me just clarify that. I think that Rand Paul represents a segment of the GOP, just like his father,” he added. “And I think he is trying to expand that, intelligently, to make it larger.”

McCain went onto say that Clinton “did a fine job” as Secretary of State (uh, Benghazi?). “She’s a rock star,” he added. “She has, maybe not glamour, but certainly the aura of someone widely regarded throughout the world.”

This is obviously another example of the fissures that have opened in the Republican Party. They don’t end with foreign policy, though that has become one of the focal points as of late. Liberty-minded Republicans in both chambers have been pushing leadership on spending and waging a hard-fought battle to defund ObamaCare.

Though he was once considered a “maverick,” McCain has become one of the loudest mouthpieces of the Republican establishment in Congress, preferring to preserve the status quo over waging potentially contenious political battles with Democrats. But whenever voters hear him talk, they run in the other direction because they see him as a cranky grandfather who is out of touch with most of America.