Mitt Romney is leading indisputably in the late night polls — late night joke-telling polls, which may be either a dubious distinction or reasonable proof of where late night hosts' political sentiments lie. (Or remotely a third option — he had a rough few weeks before the debates, like the "47 percent" comment, which maybe made his campaign an easier target.
In any case, the Center for Media and Public Affairs, which has been measuring late night joke content for years, reports this:
Mitt Romney was the target of 148 jokes on late-night talk show monologues, over twice as many as President Obama. Obama finished second with 62 jokes. The disparity was greatest on “The Late Show with David Letterman.” Letterman told 44 jokes about Romney and 9 about Obama, a five to one margin. But all four comedians told more Romney jokes than Obama jokes. There were 290 jokes about Republicans, more than twice the 138 jokes about Democrats. The Top Ten joke targets included 5 Republicans and 3 Democrats. For Barack Obama, being bypassed by TV’s humorists is nothing new. In the 2008 general election, CMPA found that he finished fourth with 243 jokes, behind GOP candidates John McCain (658), Sarah Palin (566), and outgoing President George W. Bush (244).
Here's the full count, as measured from Aug. 27 through Oct. 3: Mitt Romney (R) — 148 2. Barack Obama (D) — 62 3. Arnold Schwarzenegger — 39 4. Bill Clinton (D) -- 28 5. Paul Ryan (R) -- 20 6. Prince Harry — 19 7. Clint Eastwood (R) — 18 8. Joe Biden (D) -- 16 9. Mahmoud Ahmadinejad — 15 10. Chris Christie (R) -- 14.