Texas Governor Rick Perry, one of Mitt Romney's former rivals for the GOP presidential nomination, has formally endorsed the former Massachusetts governor for president.

Perry, after previously endorsing Newt Gingrich, now says Romney, whom he once called a “vulture capitalist,” has “earned the nomination.”

“Today I join the many conservative Republicans across the nation in endorsing Mitt Romney for president and pledge to him, my constituents and the Republican Party than I will continue to work hard to help defeat President Obama," Perry said in a statement issued Wednesday.

"American jobs, economic stability and national security depend on electing a new president. Mitt's vision and record of private-sector success will put America back on the path of job creation, economic opportunity and limited government"...

Newt Gingrich plans to formally leave the Republican presidential race next Tuesday, senior campaign aides told Fox News, after struggling for months to turn around his sagging bid for the White House.

The former House speaker will "more than likely" endorse Mitt Romney when he makes his announcement to either suspend or end the campaign, a source said.

The decision comes after Gingrich huddled with senior advisers following the five primaries Romney swept on Tuesday night. Romney's victories made it virtually impossible for Gingrich to secure the 1,144 delegates needed for the Republican nomination...

Sen. Marco Rubio, R-Fla., endorsed Mitt Romney for president Wednesday night on Fox News' "Hannity," saying Romney offers "a very clear alternative" to President Obama's vision for the future of the country.

Rubio, a young, first-termer who has been discussed as a possible vice presidential candidate, criticized talk of a fight for the Republican nomination on the convention floor, a possibility that is keeping alive the campaigns of Rick Santorum and Newt Gingrich.

"I think that's a recipe for delivering four more years of Barack Obama," Rubio told Fox News' Sean Hannity.

Romney has "earned this nomination," Rubio said, though he again shot down questions about whether he would accept any offers of a spot on the ticket...

Lake in the Hills, Ill. - Whether it's high gas prices, social security, paying off the national debt, or encouraging innovation in America, Newt Gingrich has big solutions for them all: increased domestic drilling, private savings accounts, the vision of a settlement on the moon.

Now, after two humbling defeats in Alabama and Mississippi, Gingrich told reporters he is ready to make changes to his campaign, "I think what you'll see is a much clearer definition of a visionary conservative as compared to the more traditional Romney Santorum conservatism."

But prompted for more details - would he plan to hone his message so it doesn't sound like he has an array of ideas - Gingrich said, "No, I'm going to fine tune my message to say, without vision the people perish. We need a visionary leader with very big and bold ideas.

Former Pennsylvania Sen. Rick Santorum holds a substantial lead over the rest of the Republican presidential field in Texas, according to a new poll of primary voters there.

The poll, by Wilson Perkins Allen Opinion Research, put Mr. Santorum at 35 percent support among likely voters, ahead of former Massachusetts Gov. Mitt Romney at 27 percent and former House Speaker Newt Gingrich at 20 percent. Rep. Ron Paul, a Texan, draws just 8 percent support.

Texas votes on May 29, and it is the second-biggest prize on the Republican delegate board, behind California.

Mr. Santorum's showing in the polls there likely gives him added incentive to stay in the race, following his wins in Alabama and Mississippi on Tuesday...

BILOXI, Miss – The Republican presidential primary candidates are preparing to add to their delegate totals Tuesday with two big-ticket states in the South, where Rick Santorum and Newt Gingrich need to excel to stay competitive.

Mitt Romney, on the other hand, acknowledged he doesn't need to win Alabama or Mississippi to stay in the nomination hunt even as he expressed confidence -- backed by late polling -- that evangelical and socially conservative voters in the South think he's the one to win the White House back from President Obama.

"John McCain didn't win either of these states, Alabama or Mississippi," he told Fox News. "We are delighted that we are doing so well there. The polls are suggesting it is kind of a three-way tie.

Sources close to the Gingrich campaign say preliminary "what-if" conversations are underway that could lead to a Gingrich-Perry ticket being announced prior to the Republican National Convention at the end of August.

Gingrich insiders hope forming a predetermined ticket with Perry will unite the evangelical, Tea Party and very conservative voters that make up the core of the GOP.

As discussions got underway, a spokesman for Texas Gov. Rick Perry released a statement saying, "Gov. Perry thinks Newt Gingrich is the strongest conservative to debate and defeat President Obama and truly overhaul Washington. The speculation is humbling but premature."

Floating Perry as a runningmate two days before Alabama and Mississippi could energize conservatives or turn them off.

A senior aide to Rick Santorum called it a desperate hail mary to create buzz ahead of contests in Alabama and Mississippi Tuesday...

A new poll out shows the GOP presidential race is basically a three-man tie heading into Alabama's primary on Tuesday.

In a telephone survey of 750 likely Republican primary voters in the state, Rasmussen Reports found that former House Speaker Newt Gingrich received 30 percent of the support, running slightly ahead of former Pennsylvania Sen. Rick Santorum, 29 percent, and former Massachusetts Gov. Mitt Romney, 28 percent. Texas Rep. Ron Paul brings up the rear with 7 percent.

Alabama and Mississippi, which also holds its primary Tuesday, are widely viewed as must-win states for Mr. Gingrich, who is looking to build on the momentum in the South that he's carrying from his win in Georgia, a state he represented for 20 years in Congress. Mr. Santorum also is trying to add to his delegate count in the South, where he is battling it out with Mr. Gingrich to become the conservative alternative to Mr.

Newt Gingrich could be facing a win-or-walk-away situation in the Deep South on Tuesday -- and the early numbers are not promising for the trailing presidential candidate, with two new polls showing him behind in Alabama.

The new polls each showed a different leader in the state, neither of them Gingrich. In an Alabama Education Association poll, Mitt Romney was ahead. A survey out of Alabama State University gave the lead to Rick Santorum.

Gingrich's campaign brushed off the results. But they underscore the challenge the former House speaker faces.

His entire campaign strategy rests on big wins in southern states -- the next of which, Alabama and Mississippi, vote Tuesday. Though Gingrich won big in his home state of Georgia on Super Tuesday, that strategy suffered a blow after he also lost Tennessee to Santorum. And if Gingrich loses either Mississippi or Alabama on Tuesday, or both, he could be left with an almost invisible path to the nomination...

The race for the Republican presidential nomination is about to take a big step forward, with 10 states weighing in Tuesday on the biggest day of voting yet in the two-month-old campaign.

With several key contests set for so-called "Super Tuesday" -- from the swing state of Ohio to the delegate-rich Georgia -- the four remaining candidates have pursued varying strategies for capitalizing on the day's voting and gaining momentum.

Mitt Romney remains the front-runner and could use a dominant showing Tuesday to all but eliminate doubt about his inevitability. But Rick Santorum continues to present a strong challenge, and polls have remained close in Ohio, a Midwestern industrial state where voters have an uncanny history of picking winners in presidential politics...