Seeing as how Obama and the DNC abruptly stopped their anti-Romney ads as soon as Newt overtook him in the polls, I think it’s clear who they’d prefer to run against. If they wanted Romney taken down, they’d keep pushing their anti-Romney ads and trying to knock him down. They’re much more afraid that Newt will prevail, hence they’ve shut up. In fact they put out an ad saying Newt was part of the Tea Party, obviously meant to help him in the primaries.
Sorry, I meant to say the Newt ad was obviously pulled after it only seemed to help Newt’s poll numbers and they’ve now stopped doing any ads.