[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/06/27/art.cartermccain.ap.jpg caption="McCain delivered a tough assessment of Carter."](CNN) - John McCain directed his trademark straight talk toward a former president, flatly calling Jimmy Carter a "lousy" commander in chief.
The Arizona senator has long attempted to portray Barack Obama's policies as in the mold of Carter's, though the Republican has previously held back criticizing Carter so directly.
But in an interview with the Las Vegas Sun published Friday, McCain was decidedly more blunt than he has been in the past. McCain, who is a proponent of nuclear reprocessing, was asked why he thought Carter was against the process when he was president.
"Yes, because Carter was a lousy president," McCain quipped. "This is the same guy who kissed Brezhnev."
McCain's comments are in reference to the now famous moment when Carter and then Soviet Union leader Leonid Brezhnev kissed after signing the SALT II treaty in 1979. Both the agreement and the kiss were widely panned by Republicans.
Carter himself largely stayed on the sidelines during the prolonged Democratic primary race, refusing to publicly back a candidate. Though he had long dropped several hints that he was a supporter of Barack Obama and he formally endorsed the Illinois senator shortly after he tied up the nomination.
Watch: Jimmy Carter sounds off