Barack Obama said Thursday that his 2008 presidential opponent John McCain would be seen as "too liberal" by the Republicans hoping to deny the president a second term come November.

"In 2008, I was running against a general election candidate who believed in banning torture, believed in doing something about climate change -- somebody who, frankly, could never get a nomination in the Republican Party this time out, would be considered too liberal," Obama said at a New York fundraiser.

Obama's campaign has cast the Republicans battling it out for the party's nomination as rightwing radicals out of touch with mainstream Americans.

"If you're wondering what I'm talking about, I recommend you watch the recent (Republican) debates," Obama said at the event attended by musician John Legend and Hollywood producer Harvey Weinstein.

"We're thinking about just running those as advertisements, little snippets, without commentary. We'll just sort of -- here you go, this is what they said a while back," he said to laughter.

Republican frontrunner Mitt Romney -- who served as a moderate governor of liberal Massachusetts -- has tacked to the right to fend off challenges from Christian conservative Rick Santorum and the other candidates.

Romney's apparent reversals on the issues of abortion and gay marriage -- and his criticism of Obama's healthcare overhaul, which strongly resembles his own Massachusetts reforms -- have opened him up to charges of flip-flopping.

McCain -- long seen as a moderate "maverick" inside the Republican party -- adopted a similar strategy in 2008, shedding a more centrist view on immigration in order to rally his party's conservative base.

This year's Republicans are set to square off on Super Tuesday next week, when 10 states vote simultaneously on the biggest day yet for the 2012 nomination battle.