President Obama's administration launched a multipronged assault on Mitt Romney's values and foreign policy credentials Sunday, while a fresh set of prominent Republicans rallied behind the GOP presidential front-runner as the odds-on nominee, further signs that the general election is overtaking the primary season.
A defiant Rick Santorum outlined plans to leave Wisconsin the day before the state's primary Tuesday, an indication that the conservative favorite may be in retreat, his chances to stop Romney rapidly dwindling.
"I think the chances are overwhelming that [Romney] will be our nominee," Senate Minority Leader Mitch McConnell, R-Ky., said Sunday on CNN's "State of the Union."
"It seems to me we're in the final phases of wrapping up this nomination. And most of the members of the Senate Republican Conference are either supporting him, or they have the view that I do -- that it's time to turn our attention to the fall campaign and begin to make the case against the president of the United States."
Both Vice President Biden and Secretary of State Hillary Clinton went after Romney on Sunday, underscoring the belief inside Obama's Chicago re-election headquarters that Romney will -- sooner than later -- secure the right to face Obama this fall. Their involvement comes as both sides sharpen their general election strategy, perhaps weeks before the GOP contest formally comes to an end.
"I think Gov. Romney's a little out of touch," Biden told CBS' "Face the Nation" in an interview broadcast Sunday. "I can't remember a presidential candidate in the recent past who seems not to understand, by what he says, what ordinary middle-class people are thinking about and are concerned about."
Obama's team also seized on the former Massachusetts governor's foreign policy inexperience. Clinton reacted to Romney's comment that Russia is America's "No. 1 geopolitical foe," calling the statement "dated" and suggesting that there were more pressing matters of concern in global affairs.
"I think it's somewhat dated to be looking backwards instead of being realistic about where we agree, where we don't agree," Clinton told CNN.
"He just seems to be uninformed or stuck in a Cold War mentality," Biden added. "It exposes how little the governor knows about foreign policy."
But the Obama administration's comments may have been overshadowed Sunday by Romney's ballooning GOP support.
House Budget Committee Chairman Paul D. Ryan, R-Wis., spent the weekend at Romney's side campaigning across Wisconsin, one of three states to host GOP primaries Tuesday. First-term Sen. Ron Johnson, R-Wis., followed Ryan's lead.
Ryan's endorsement was particularly painful for Santorum, who had been aggressively praising the congressman -- a fiscal conservative hero in Wisconsin and across the country -- for much of the last week. That praise ended Saturday, when Santorum referred to Ryan as "some other Wisconsinite."
Santorum's staff outlined an increasingly unlikely path to victory that depends on hypothetical success more than a month away. "May is going to be a good month for us," Santorum campaign manager Mike Biundo said.
A defiant tone was struck by Santorum. "Look, this race isn't even at halftime yet," the former Pennsylvania senator told "Fox News Sunday." He said Romney "hasn't been able to close the deal with conservatives, much less anybody else in this party. And that's not going to be an effective tool for us to win this election."