Along the Wisconsin campaign trail on the eve of Tuesday's primary, Republican presidential hopeful Mitt Romney has not been alone.

Wisconsin Republican Reps. Paul Ryan and Jim Sensenbrenner and freshman Sen. Ron Johnson, a Tea Party favorite, are appearing alongside Romney, introducing him at town hall meetings and urging Wisconsinites to help bring the lengthy primary fight to a close by supporting the former Massachusetts governor.

In a race where many current congressional lawmakers have remained on the sidelines, Tuesday's Wisconsin primary represents a shift within the Republican leadership. Many GOP lawmakers are signaling by their words and their appearances that they want the contentious primary season to end so that the party can focus its attacks on President Barack Obama rather than on each other.

Voters seem to agree in Wisconsin, where Romney has pulled ahead of top challenger Rick Santorum by seven points in the latest polls. Maryland and Washington, D.C., also hold Republican contests on Tuesday, and Romney has strong leads in both places.

Romney currently has 572 delegates, according to the Associated Press. That is exactly half of the 1,144 needed to win the GOP nomination and more than twice as many as Santorum's 272 delegates. Newt Gingrich and Ron Paul, two other Republican hopefuls still in the race, remain way behind in the delegate count and also trail in Tuesday's primary contests.

If a Romney sweep occurs on Tuesday, will Santorum yield? Not likely.

Despite intensifying calls from party leaders for Republican unity, Santorum spent Monday arguing that a protracted primary fight will strengthen the party.

"Cutting it short and getting the wrong candidate is worse than making this a fight for the heart and soul of America, and the heart and soul of the Republican primary," he said Sunday to supporters in Green Bay, Wis.

The next day Santorum took his case to the media, telling reporters in Appleton, Wis., that a battle all the way to the Republican convention in August "would be a fascinating display of open democracy."

"I think it would be an energizing thing for our party to have a candidate emerge who isn't the blessed candidate of the Republican establishment," he continued. "It's a good narrative for us … the shorter this election in the fall, the better off we are, not the worse."

But there are plenty of signs that current Republican leaders do not agree. Romney will start raising money this week with the Republican National Committee. The move allows donors to give as much as $75,000-far more than the current $2,500 individual donation limit-by giving to both the party and the candidate. The latest fundraising reports show Obama with $84.7 million in his campaign account compared to Romney's $7.3 million.

Senate Republican Leader Mitch McConnell, while not outright endorsing Romney, said Sunday on CNN, "It seems to me we are in the final phases of wrapping up this nomination. … It is in the best interest of our party to get behind the person who is obviously going to be our nominee and make the case against the president of the United States."

Obama's campaign is also starting to target Romney-criticizing him by name for the first time in a campaign ad released Monday. The commercial, scheduled to run in six swing states, accuses Romney of being an ally of the oil companies.

While Santorum spent time in Wisconsin making his case for staying in the race, Romney found himself on Monday defending his religious beliefs.

Romney mostly has refrained from discussing his Mormon faith, but a Ron Paul supporter questioned him about Mormonism during a Monday campaign stop in Green Bay.

"I'm sorry, we're just not going to have a discussion about religion in my view," Romney responded.

When the Paul supporter, Bret Hatch, next asked Romney if he thought it was a sin for interracial couples to have children, Romney replied, "No. Next question."

But later in the event, Romney returned to his Mormon beliefs:"This gentleman wanted to talk about the doctrines of my religion. I'll talk about the practices of my faith. I had the occasion in my church to be asked to be the pastor, if you will, of a congregation. And I've served in that kind of role for about 10 years. And that gave me the occasion to work with people on a very personal basis that were dealing with unemployment, with marital difficulties, with health difficulties of their own and with their kids."

The exchange gave a hint of how he may tackle questions about his Mormon beliefs if he were to take on Obama this fall.