Romney rolls

Mitt Romney's sweep of three primaries on Tuesday, including top prize Wisconsin, lengthens the frontrunner's delegate lead and has many declaring the 2012 Republican presidential primary race all but over.

"We won 'em all," Romney told supporters in Milwaukee, after he had been declared the winner in that state, as well as in Maryland and the District of Columbia.

In his victory speech, the former Massachusetts governor did not linger long on the day's victories, or on his Republican rivals. Instead he went right at President Barack Obama, repeating a strategy that he has tried with every significant primary victory.

But Tuesday's speech had a different feel, with less lines devised to whip up the crowd and more talk contrasting his experiences with Obama's in handling what will be the biggest issue of the race: the economy.

Romney blamed Obama for job losses and high gas prices, describing the president as out of touch and determined to transform America into a government-centered society.

"Under Barack Obama America hasn't been working," Romney said. "In Barack Obama's government-centered society, the government has to do more because the economy is doomed to do less. When you attack business and vilify success you are gong to have less business and less success."

Romney, who repeatedly referred to Obama's past as a community organizer, assured conservatives that he wants to "restore the values of economic freedom and opportunity and limited government that have made this nation the leader it is."

Romney's chief GOP rival, Rick Santorum, had already left Wisconsin, a state he had campaigned in heavily in the weeks leading up to the primary.

Santorum appeared Tuesday in his home state of Pennsylvania, signaling that its April 24 primary is a must-win for the former senator. The two other contenders, Newt Gingrich and Ron Paul, finished far behind Romney in all three contests Tuesday.

A parade of political pundits on television news channels Tuesday night urged Santorum to drop out of the race. But Santorum is hoping a win in Pennsylvania will carry him through May when several pro-Santorum Southern states hold their primaries.

"We have now reached the point where it's halftime," Santorum told supporters in Mars, Pa. "And who's ready to charge out of the locker room in Pennsylvania for the second half?"

Santorum's sustained argument is that Republicans need to pick a nominee who provides a more conservative contrast to Obama.

"We don't win by moving to the middle," he said.

Wisconsin exit polls show that Romney is gaining support among voters who describe themselves as conservative, winning 48 percent of that vote compared to Santorum's 40 percent. The two candidates tied among voters who describe themselves as very conservative, each capturing 43 percent. Like he did in Michigan and Illinois, Romney won support of Tea Party voters in Wisconsin.

But Romney still has some work to do among the most conservative members of the party: Wisconsin voters who said that being a true conservative was the most important candidate trait went for Santorum over Romney by a sizeable 61 percent to 13 percent margin. By contrast, Romney garnered 67 percent of the vote from those who said beating Obama was the top candidate trait; Santorum mustered support from just 23 percent of those voters.

Santorum's strength also has rested on his appeal to working class voters and evangelicals. In Wisconsin, Romney made inroads among voters who lack a college degree and those with a household income less than $50,000 a year, narrowly winning both those categories after Santorum had won them in earlier Midwestern contests. With these gains among working class and Tea Party voters, Romney may be becoming more accepted among a wider array of Republicans.

The lone Romney holdouts, according to Wisconsin exit polls, are evangelical voters. Santorum, a devout Catholic, again won that category, but the margin is shrinking. In previous contests in Michigan, Oklahoma, Ohio, and Tennessee, Santorum took the evangelical vote by double-digit margins. In Illinois on March 20, he won evangelicals by 7 percentage points over Romney. And in Wisconsin, Santorum's lead among evangelicals slipped again to just a 5 percent edge, 43 percent to 38 percent.

But what has boosted Romney as much as his primary wins has been the string of endorsements from top Republican lawmakers. In the last week, he has gained the backing of House Budget Committee Chairman Paul Ryan, Sen. Ron Johnson, former Florida Gov. Jeb Bush, former President George H.W. Bush, Sen. Marco Rubio, House Majority Whip Kevin McCarthy and Sen. Mike Lee. More are expected in the aftermath of Tuesday's victories.

These lawmakers may be stepping forward now over concerns that a protracted GOP fight only strengthens Obama. A recent CNN/Opinion Research poll has Obama ahead of Romney by 11 points nationally, 54 percent to 43 percent.

Romney's endorsers also are encouraged by his victories in industrial states like Wisconsin, Michigan, Ohio, and Illinois. Those states will be important battleground states in November.

Santorum on Tuesday night tried to dismiss the endorsements: "Time and time again the Republican establishment and aristocracy have shoved down the throats of the Republican Party and people across this country moderate Republicans."

But many of Romney's new backers are not part of the party's old guard: Sens. Johnson, Rubio, and Lee are all freshmen lawmakers who have strong Tea Party backing. Conservative leader Sen. Jim DeMint, while not officially endorsing Romney, also has been publicly praising him.

The primary fight's center stage now shifts to the April 24 showdown on Santorum's home turf in Pennsylvania. A Santorum win there would likely allow him to push the race until June, even though Romney's delegate lead will be hard to catch. Meanwhile, a win for Romney in Pennsylvania would likely allow him to start marshaling resources solely for this fall's showdown.

Listen to a report on Mitt Romney's primary victories on WORLD's radio news magazine The World and Everything in It.