[cnn-photo-caption image= http://i.l.cnn.net/cnn/2008/images/02/01/art.coulter.gi.jpg caption=" Ann Coulter said Thursday she'd back Hillary Clinton over John McCain."]
(CNN) - In the latest sign that a conservative backlash is starting to build against John McCain, conservative commentator Ann Coulter said Thursday she is prepared to vote for Hillary Clinton over the Arizona senator in a general election match up.
Speaking on Fox's "Hannity and Colmes," Coulter took aim at the GOP frontrunner, and suggested he was little more than a Republican in name only.
"If you are looking at substance rather than if there is an R or a D after his name, manifestly, if he's our candidate, than Hillary is going to be our girl, because she's more conservative than he is," Coulter said. "I think she would be stronger on the war on terrorism."
Coulter took aim at McCain's positions - particularly his fervent anti-torture stance - and said he and Clinton differ little on the issues. Coulter also said she is prepared to campaign on Clinton's behalf should McCain win the party's nomination.
"John McCain is not only bad for Republicanism, which he definitely is - he is bad for the country," she said.
Coulter is the latest high profile conservative to express dismay with McCain's surging candidacy. Talk-radio host Rush Limbaugh said Wednesday McCain's rise was the product of a 'fractured' conservative base and an "uninspiring" GOP presidential field.
"He is not the choice of conservatives, as opposed to the choice of the Republican establishment — and that distinction is key," Limbaugh continued. "The Republican establishment, which has long sought to rid the party of conservative influence since Reagan, is feeling a victory today as well as our friends in the media."
McCain has long been at odds with conservative members of his party. — Exit polls from the early-primary states have shown the he has consistently lost among those primary voters who identify themselves as conservative. But he passed a key test Tuesday in winning Florida's primary, the first early contest that only allowed registered Republicans to participate.
Reacting to criticisms from his party's most conservative quarters, McCain told the San Francisco Gate Thursday, "I'll continue to reach out to all in the party, try to unite the party, until everybody realizes that the only way we're going to defeat the Democratic candidate is through a united party."
- CNN Producer Alexander Mooney