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Newt Gingrich laid a stark attack on his rival in the run-up to Florida's "winner-take-all" Republican presidential primary Tuesday, accusing Mitt Romney of being no different than President Obama and suggesting the front-runner will be a threat to religious freedom.

As Romney seeks to tighten his grip on the Republican presidential nomination, charging ahead by double-digits in most late polling in Florida, Gingrich told Fox News on Monday that Romney's decision while Massachusetts governor to cut Medicaid funding for health care services that benefited Jewish and Catholic facilities demonstrated that he has little respect for religion. He added that the trend is for a secular state assault on people of faith.

"I think Gov. Romney is extraordinarily insensitive to religious freedom in America and the Obama administration is clearly engaged in a war on religion," said Gingrich, a converted Catholic.

Gingrich said he attended Mass in Jacksonville on Sunday at one of several churches across the state where a letter was read about "the Obama administration's assault on the Catholic Church."

"People don't understand yet how much the secular state is becoming an anti-religious instrument of coercion," he told Fox News' Bret Baier.

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    In heavily Jewish Florida, Romney's camp responded to the Gingrich comments by distributing a bullet-point list of items Romeny has said in defense of Israel. It also noted that the Medicaid funding was restored before any services were cut.

    Romney, enjoying a stunning turnaround in fortunes just 10 days after Gingrich's overwhelming victory in South Carolina, repeated the charges that Gingrich is "flailing" in the face of a collapsed campaign. He said Gingrich's charges against him reflect the state of his campaign.

    "It's really sad," Romney told Fox News. "In some respects I think it's painfully revealing that (Gingrich) is having a really hard time."

    Romney added that he is "pleased" with the results so far out of Florida.

    "This has been an aggressive campaign here in Florida," he said. "I got beaten pretty heavily in South Carolina by very strong attacks. We came back and responded, and made sure that my message got through, and I'm pleased with the fact that at this stage I'm getting a great response from the people in Florida."

    Polling stations opened at 7 a.m. ET in the Sunshine State, which has already had more than 600,000 people participate in early polling. The GOP primary is expected to outdo the 2008 race with as many as 2 million votes cast in the high-stakes, high-profile election.

    Even with a Romney victory Tuesday, as the race shifts to a series of lower-profile contests in February, Gingrich has said he's prepared to stay in the contest through to the convention this summer, when the party officially selects its nominee to challenge Obama.

    "The conservative movement is not going to sit back and say, 'Oh yes let's let Wall Street and Mitt Romney buy the election,'" Gingrich said. "You're going to see a real grassroots fight. It will be people power vs. Goldman Sachs and Mitt Romney."

    But with two second place finishes and a victory in New Hampshire, Romney has suggested the wind is at his back.

    "With a turnout like this, I'm beginning to feel we might win tomorrow," an upbeat Romney told a crowd of several hundred at a stop in Dunedin on Monday.

    Romney's campaign canceled a Tuesday morning rally, but scheduled a night celebration at the Tampa Convention Center. Gingrich will make a series of public appearances, including visits to two polling stations and a stop at the Polk County headquarters, before gathering with supporters for a primary night party in Orlando. The last polls close at 8 p.m.

    The other two candidates in the race will not be in Florida on Tuesday. Both Rick Santorum and Ron Paul have ceded Florida's primary to Romney and Gingrich in favor of smaller, less expensive contests. They will spend the day campaigning across Colorado and Nevada.

    Santorum told Fox News' Bill O'Reilly Monday that he feels the race is still up for grabs.

    "I think one thing we do know about this race is if you don't like what's going on in the race wait a week or two," he said. "We have seen this race change literally a dozen times."

    He added on Monday morning that everyone should stay in the race as long as they want, after Gingrich suggested Santorum should drop out and throw his support to him.

    "This is only the fourth state," he said. "Let's take our time, let's make sure that the best candidate rises up, and I think in the end we'll be that best candidate."

    Romney and his allies have poured more than $14 million into Florida television advertising primarily to attack Gingrich, who has struggled to compete with Romney's fundraising ability, staffing and network of high-profile supporters. Gingrich and his allies spent roughly $3 million on Florida advertising.

    "We are pitting people power versus money power," Gingrich said.