The U.S. Senate's top Republican called on his party to unite behind leading presidential candidate Mitt Romney on Sunday as rival Rick Santorum vowed to stay in the race beyond a likely defeat in Tuesday's Wisconsin primary.
Senate Republican Leader Mitch McConnell stopped short of endorsing Romney in an interview on CNN's "State of the Union" show. But McConnell did say the former Massachusetts governor would make an "excellent nominee" and left little doubt about whom he supported in the battle to take on Democratic President Barack Obama in the November 6 election.
"It's time to turn our attention to the fall campaign and make the case against the president of the United States. "It's important to get behind the person who is obviously going to be our nominee," McConnell said, referring to Romney.
A victory in Wisconsin's Tuesday primary would give Romney an almost insurmountable lead in the Republicans' state-by-state nominating contest. McConnell joined a chorus of other top Republicans who have called for the nominating process to wind down.
Santorum said a defeat in Wisconsin would not force him from the race and predicted he would do well in May, when several conservative states hold their primaries.
"The map in May looks very, very good for us," the former Pennsylvania senator said on "Fox News Sunday."
Santorum said the Democrats had been strengthened in 2008 by a primary battle that stretched to June, when Republicans had wrapped up their nomination by March.
"Four years ago, everybody said, 'Oh, we've got to wrap this up,' and we did and John McCain was the nominee, and Barack Obama and Hillary Clinton went into the summer and pounded it out and guess what? They came up with the best candidate, we came up with somebody who, well, just simply wasn't able to win," he said.
BIG DELEGATE LEAD
In the state-by-state battle to accumulate the 1,144 delegates needed to win the nomination, Romney has an estimated 565 delegates while Santorum has 256, according to Real Clear Politics. Former House of Representatives Speaker Newt Gingrich has 141 delegates, while Representative Ron Paul has 66.
Both Gingrich and Paul said they would stay in the race as well, with the goal of denying Romney a clear majority of delegates ahead of the August convention in Tampa.
"Who knows what will happen with the first vote at the convention," Paul said on CBS's "Face the Nation."
Democrats have focused their attacks on Romney, portraying the millionaire former businessman as out of touch with regular voters.
"I can't remember a presidential candidate in the recent past who seems not to understand ... what ordinary middle-class people are thinking about and are concerned about," Vice President Joe Biden said on CBS's "Face the Nation."
Polls show Romney leading in Wisconsin, Maryland and the District of Columbia, all of which hold primaries on Tuesday.
Romney picked up an endorsement on Sunday that could help: Senator Ron Johnson of Wisconsin, who has ties to the state's grassroots conservative Tea Party movement. Another prominent Wisconsin lawmaker, House Budget Committee Chairman Paul Ryan, also has endorsed Romney.
"I think conservatives should coalesce around the Romney campaign and move on to the general election," Ryan said on CNN. "I hope a big victory on Tuesday will do just that."
Gingrich said he would back Romney if he won the nomination, but Paul said he was not sure.