Mitt Romney seeks big wins to elbow out Rick Santorum

Mitt Romney charged toward the Republican US presidential nomination on Tuesday, shooting for big victories in Wisconsin and two other contests that would increase the pressure on rival Rick Santorum to drop out of the race.

Romney leads in polls in Wisconsin, Maryland and Washington DC, the latest contests in the grinding, months-long battle for the right to face Democratic President Barack Obama in the November 6 election.

A sweep of all three would underscore Romney's growing strength and likely increase appeals from party leaders for Republicans to rally behind him despite deep reservations among many conservatives suspicious about whether he is one of them.

Practically, winning all three contests would give Romney 95 more delegates and put him at well over half of the 1,144 needed to clinch the nomination at the party's convention in August.

And it would set the tone for the next big date on the campaign calendar, April 24, when six states hold Republican presidential contests. Romney leads in five of them and plans to make an aggressive push in the sixth, Santorum's home state of Pennsylvania. Romney travels there on Wednesday.

Although Romney has locked up support from much of the Republican party establishment, he has struggled to win over strict conservatives, many of whom favor Santorum.

Sarah Palin, the conservative former governor of Alaska and 2008 Republican vice presidential nominee, said the nominating process could still veer away from the front-runner.

"Anything is still possible, there can still be a bit of a shakeup," she said on NBC's "Today" program.

Palin said whoever becomes the nominee -- Romney or one of his rivals -- would get the support of the Republican base.

"He (Romney) will be able to do that," she said. "If not Romney, if one of the other GOP candidates happen to surpass Romney in the delegate count ... whomever will be able to coalesce, we will be able to coalesce around that nominee and make sure that voters understand they have a choice here."

Wisconsin is the most closely watched race of the trio voting on Tuesday. Santorum, a conservative former US senator, has campaigned heavily in the state and had led in the polls until ceding the lead to the Romney, the former Massachusetts governor and private equity executive, in the last week or so.

Sensing the nomination is in sight, Romney has made no mention in recent days of Santorum or his other Republican rivals, Newt Gingrich and Ron Paul. Romney has instead pivoted to a general election campaign against Obama over the president's handling of the US economy.

In an appearance on Fox television, Romney addressed concerns that Obama would fare better with women voters in a general election after a poll showed the president with a large advantage among women voters in swing states.

"You realize that under this president the number of new business startups per year has dropped by 100,000," Romney said. "It has been a war on enterprise, a war on jobs, and it's time for that to end if we're going to get women back to having good jobs and rising incomes."

ROMNEY VS OBAMA

While the economy has been showing signs of progress, Romney says high unemployment, high poverty and burdensome regulations remain serious challenges that prove Obama has been a failure.

Obama's campaign said Romney was out of touch.

"You have a guy who wants to go back to the same policies that got us into this (economic) disaster," Obama campaign strategist David Axelrod said on CBS.

"He wants to cut taxes for the very wealthy, cut Wall Street loose to write its own rules and he thinks that this somehow is going to produce broad prosperity for Americans. We've tested that. It's failed."

Obama's campaign released an ad this week targeting Romney directly for backing oil companies and opposing higher mileage standards for vehicles.

If he does win the nomination, Romney would face the challenge of defeating an incumbent president whose campaign operation is well-funded, organized and eager to pounce on any misstep.

Santorum wants to survive Wisconsin and the rest of April and move on to May, where the states that vote may be more favorable to him. He would have to win an overwhelming percentage of the remaining delegates to win the nomination outright.

But Santorum seems to have a different strategy: Win enough delegates to deny outright victory to Romney. This would force Republicans to choose their candidate at a "brokered" convention in Tampa, a chaotic scenario that many political experts believe could be disastrous to the party's hopes of ousting Obama.

"I would argue even if it ends up in a convention, that's a positive thing for the Republican Party, that's a positive thing for activating and energizing our folks heading into this fall election," Santorum told reporters on Monday.

Trying to appeal to blue-collar voters, Santorum has held small campaign events in Wisconsin, frequently appearing in bowling alleys. He insists he is staying in the race and has been relentless in trying to brand Romney as a Massachusetts moderate who would govern little differently than Obama.

Romney has benefited from the endorsement in Wisconsin of Paul Ryan, a popular conservative from the state who is chairman of the powerful House of Representatives Budget Committee.

The two men have appeared side by side at a number of campaign events and appear to have a warm relationship, leading to news media speculation that Ryan may be on Romney's short list for the vice presidential nomination.