04/25/2012 10:22 am ET Updated Apr 25, 2012

Obama: Romney Can't Say 'Everything I've Said For The Last 6 Months, I Didn't Mean'

President Barack Obama framed the 2012 election in some of the starkest terms to date in an interview published Wednesday by Rolling Stone.

Obama said that in this election there "will be as sharp a contrast between the two parties as we've seen in a generation."

"You have a Republican Party, and a presumptive Republican nominee, that believes in drastically rolling back environmental regulations, that believes in drastically rolling back collective-bargaining rights, that believes in an approach to deficit reduction in which taxes are cut further for the wealthiest Americans, and spending cuts are entirely borne by things like education or basic research or care for the vulnerable," Obama continued.

Obama rejected the idea that Mitt Romney would be able to disavow positions he's taken in the primary. "I don't think that their nominee is going to be able to suddenly say, 'Everything I've said for the last six months, I didn't mean.' I'm assuming that he meant it," he said. "When you're running for president, people are paying attention to what you're saying."

(Above, Obama discusses Romney with Jimmy Fallon)

The notion that Romney would shift to the middle in the campaign was most famously espoused by his top adviser, Eric Fehrnstrom, who said that Romney's positions in the primary were as erasable as a drawing on an Etch a Sketch.

Romney already shifted his position on student loans, agreeing with Obama's push to extend federal interest rates at 3.4 percent after making the case in March that taxpayers should not subsidize loans at below-market rates. Rates are set to double to 6.8 percent in July.

Obama was asked about Romney Tuesday night in an interview with Jimmy Fallon. "I've met him, but we're not friends," he said. "His wife is lovely." He added that Romney was someone who "cares deeply about his family."

It was the magazine's fourth interview with Obama and lasted an hour.

Read the full interview here.