McCain: Voting between Rand Paul and Hillary Clinton would be 'tough choice'

Sen. John McCainJohn McCainIs Georgia turning blue? High anxiety for GOP Trump: 'Very disappointed' GOP senator dropped support MORE (R-Ariz.) joked that it would be a tough decision to vote for Sen. Rand PaulRand PaulWhat the 'Bernie Sanders wing of the GOP' can teach Congress GOP senators avoid Trump questions on rigged election How low is the bar for presidential candidates, anyway? MORE (R-Ky.) over Democrat Hillary ClintonHillary Rodham ClintonTrump lands first major newspaper endorsement Clinton: Trump's election talk poses 'threat to our democracy' Clinton reacts to the Chicago Cubs clinching World Series spot MORE if both won their party’s presidential nomination in 2016.

“It’s gonna be a tough choice,” McCain said with a laugh when asked about it in an interview with the New Republic published Tuesday. 

McCain clarified that he believes Paul is trying to expand the GOP brand, and that he represents the same libertarian-leaning part of the party once represented by his father, former Rep. Ron Paul (R-Texas).

However, McCain heaped praise on another prospective Republican presidential candidate in 2016, Sen. Marco RubioMarco RubioNew York Times endorses Rubio's rival Rubio: GOP Congress could go in different direction than Trump Poll: Clinton holds 4-point lead in Florida MORE (Fla.). He called Rubio a “valuable candidate for president” and said his push for immigration reform will not impede his presidential prospects, harkening back to his own failed bid in 2008.

“He has a bright future in the party,” he said. “He is a valuable candidate for president. Some people say this will set him back, but remember, I got the nomination of the party after failing on immigration in 2007.”

McCain has had numerous dustups this year with the Tea Party-fueled wing of the GOP this year. He opposed Paul’s filibuster of CIA director John Brennan’s nomination over the U.S. use of drones, and described Paul, Sen. Ted CruzTed CruzIs Georgia turning blue? Five takeaways from money race Club for Growth: Anti-Trump spending proved to be 'good call' MORE (R-Texas) and Rep. Justin AmashJustin AmashLawmakers press Lynch for briefing on Yahoo secret email scanning reports House Freedom Caucus member slows floor business House votes to block Gitmo transfers MORE (R-Mich.) as “wacko birds.”

In the interview, he said the isolationist wing of the GOP has been strengthened by the recession.

“There was an isolationist wing that fought against Reagan. And now the bad economy has exacerbated what has always been out there,” he said.

McCain attempted to separate Paul’s brand of conservatism from his former running mate in 2008, Sarah Palin, arguing her message was positive.

“They came to power to keep things from getting done,” McCain said.

Reflecting on his own legacy, he said he has had the best ride, but still expressed some regret from his failed 2008 bid for president.

“Am I happy? I’d like to be president of the United States,” he said.