Front-runner Mitt Romney closes in on Republican nomination after winning three more primaries

Romney will face a better organized, better financed Obama campaign backed by the power of the presidency (AP)

Mitt Romney tightened his grip on the Republican presidential nomination last night, sweeping primaries in Wisconsin, Maryland and Washington DC, and shifted his focus to the general election with a sharp attack on President Barack Obama.

The victories enabled Romney to pad his already considerable delegate lead over chief Republican rival Rick Santorum, who flashed defiance in the face of growing pressure to abandon his own candidacy in the name of party unity.

Despite the setbacks, Santorum, a former Pennsylvania senator, told supporters in his home state that he does not intend to quit the race.

Wisconsin was the marquee contest of the night, the only place of the three voting on Tuesday where Santorum mounted a significant effort. Romney's victory there marked his fourth in little more than a month in a belt of Midwestern industrial states that also included Michigan, Ohio, and Illinois.

Returns from 95 percent of Wisconsin's precincts showed Romney with 42 percent of the vote to 38 percent for Santorum, 12 percent for Texas Rep. Ron Paul and 6 percent for Newt Gingrich, the former speaker of the House of Representatives.

Returns from 99 percent of Maryland's precincts showed Romney with 49 percent of the vote to 29 percent for Santorum, 11 percent for Gingrich and 10 percent for Paul.

With all precincts counted in Washington, Romney had 70 percent of the vote to 12 percent for Paul and 11 percent for Gingrich. Santorum was not on the ballot.

For Romney, the end of the contested primary campaign could hardly come soon enough. Obama has gained in the polls in recent months, particularly among women, as Republicans vie among themselves for support from the party's increasingly conservative base. Santorum has devoted more time to social issues — including birth control — than Romney, who has generally stayed focused on economic issues.

Additionally, surveys indicate Americans are growing more optimistic about the overall state of the economy. Unemployment has fallen in recent months, but it is still at a relatively high 8.3 percent of the work force.

Romney and Obama exchanged barbs on Tuesday in further acknowledgement that both camps think the fall campaign for the general election has already begun.

“Four more years?” Romney asked sarcastically of the president as supporters cheered him in Milwaukee.

He said Obama was “a little out of touch” after spending four years surrounded by the trappings of power and had presided over near-record job losses as well as increases in poverty, home foreclosures, government debt and gasoline prices.

Romney, who has cemented his lead over Santorum through overwhelming spending on television advertising, will face a better organized, better financed Obama campaign backed by the power of the presidency.

Increasingly, Romney and many senior figures in his party have begun behaving as if the primaries are an afterthought, hoping to pivot to the fall campaign and criticism of Obama.

“He gets full credit or blame for what's happened in this economy and what's happened to gasoline prices under his watch and what's happened to our schools and what's happened to our military forces,” Romney said of the president while campaigning in Waukesha, Wisconsin.

Obama said things could be worse — and predicted they would be if Romney and Republicans got their way.

In a speech to the annual meeting of The Associated Press, he said a budget plan passed by the Republican-controlled House of Representatives was “antithetical to our entire history as a land of opportunity and upward mobility for everybody who's willing to work for it ... It is a prescription for decline.”

When he wasn't focusing his rhetoric on Obama, Romney prodded Santorum to quit the race, suggesting a refusal to do so could cost the party the election in November.

“The right thing for us, I think, is to get a nominee as soon as we can and be able to focus on Barack Obama,” Romney said in an interview with Fox News.

Santorum, in his home state of Pennsylvania, took note of the calls for him to exit the race. He vowed to stay in the race to compete in the Pennsylvania primary on April 24 and in primaries next month on more favorable terrain in Texas, Arkansas, and other southern states. But the latest losses made it all but impossible for him to secure enough delegates to block Romney's nomination.

“Ladies and gentleman, Pennsylvania and half the other people in this country have yet to be heard, and we're going to go out and campaign here and across this nation to make sure that their voices are heard in the next few months.”

Romney won at least 83 delegates in Tuesday's three races, with six delegates yet to be decided.

That pushed his total to 655 of the 1,144 delegates needed to clinch the nomination at the Republican National Convention in late August in Tampa, Florida. Santorum has 278 delegates, Gingrich 135 and Paul 51.

Romney has won 58 percent of the primary and caucus delegates so far. He is on pace to reach the number of delegates needed to clinch the nomination in early June. Santorum has won just 26 percent of the delegates so far. He would need 80 percent of the remaining delegates to clinch the nomination — a nearly impossible task because most states award delegates proportionally.

Interviews with voters leaving Republican polling places in Maryland and Wisconsin showed an electorate more concerned with a candidate's ability to ability to defeat Obama than with the strength of his conservatism, his moral character or his stand on the issues. Similar soundings in earlier states have consistently worked to Romney's advantage.

Voters in both states were less apt to be born again or evangelical Christians than in most previous contests — 37 percent in Wisconsin and 33 percent in Maryland. Based on earlier contests, that, too, suggested an advantage for Romney. Santorum, a staunch social conservative, has done well with evangelical Christians because of his strong opposition to abortion and gay rights.

Santorum made little or no effort in Maryland, was not on the ballot in Washington, D.C., and concentrated much of his time in Wisconsin in rural areas.

He all but conceded defeat in advance in Wisconsin, retreating to Mars, Pennsylvania, for an election night appearance in his home state.

Wisconsin was the fourth industrial state to vote in a little more than a month after Michigan, Ohio and Illinois, a string that Romney has exploited to gain momentum as well as a growing delegate lead in the campaign for the Republican presidential nomination. He and a super political action committee supporting him have greatly outspent his rivals in state after state.

Romney and his allies have spent $53 million on television advertising so far this election cycle compared to $27 million from his three Republican competitors combined, according to data compiled by the media tracking firm SMG Delta.

AP