NEW YORK (AP) — David Letterman is reassuring Mitt Romney that he doesn't hate him — and getting in a dig at Jay Leno in the process.

The Republican presidential candidate said in a private speech to donors made public this week that Letterman "hates me because I've been on Leno more than him."

Letterman said on the "Late Show" Wednesday that Romney and his wife are welcome on his CBS late-night show. Romney has been on three times but hasn't made any appearances since he became GOP nominee. Democratic President Barack Obama was on Letterman on Tuesday.

Letterman says he certainly doesn't hate Romney for going on Leno's NBC show. Says Letterman: "I mean, why hate a guy who's suffered through that?"