Texas has 155 delegates at stake in its Republican primary election, and Romney needs less than half of those to put him past the 1,144 threshold needed for the nomination.

With no real rivals left, Romney should get enough delegates to put him over the top, after a long, winding campaign battle for the White House that has seen him outlast a series of conservative opponents.

A Lone Star state win will generate a positive buzz for Romney, who is holding his own against Obama despite intense attacks against the Republican’s record as a private equity executive and former Massachusetts governor.

Romney will not be in Texas on Tuesday. Instead, he will be campaigning in Las Vegas with a conservative rival he defeated for the nomination, Newt Gingrich, and real estate tycoon Donald Trump.

That may be an awkward meeting after Trump embarrassed Romney by saying that Obama was not born in the United States, a claim Romney does not agree with.

Romney refused on Sunday night to condemn Trump.

“You know, I don’t agree with all the people who support me. My guess is they don’t agree with everything I believe in. But I need to get 50.1 percent or more, and I’m appreciative to have the help of a lot of good people.”

Romney will also meet billionaire casino owner and Republican financial backer Sheldon Adelson in Las Vegas, a campaign aide said. Adelson and his family gave $21.5 million to a “Super PAC” group that supported Gingrich during the Republican primaries.

Winning the nomination will put to rest any lingering suggestion that Romney could face a conservative challenge at the Republican convention in Florida in late August as Gingrich had threatened to do when the race was still close.

“It means he is bullet-proof,” said Republican strategist Ron Bonjean.

CONSERVATIVES’ WARINESS

Romney is trying to overcome wariness among conservatives, who mistrust his record in Massachusetts where he introduced a healthcare reform that they say was a blueprint for Obama’s 2010 U.S. healthcare overhaul program that was approved in Congress despite heavy Republican opposition.

“I was looking forward to voting for Rick Santorum,” said voter Dan Cortez in San Antonio. He said he would now back Romney, for he believes it is important to elect “anybody who can beat Obama.”

Reaching the figure of 1,144 delegates will allow Romney and his campaign to help line up convention speakers and negotiate the party’s policy platform with the Republican National Committee.

It also sets up a five-month race to Election Day that is well underway, with Obama attempting to define Romney as a heartless corporate raider for his work at Bain Capital, a private equity firm.

Romney and the Republicans are running even with Obama and the Democrats in raising money in what should ensure an even playing field in television advertising that will be critical in swaying voters in the months ahead.

Romney is keeping his sights trained on Obama’s handling of the tepid U.S. economy, a strategy that appears to be helping him in an uphill fight to unseat a sitting president. Polls show voters give Romney the nod over Obama when asked who would better manage the economy.

The Romney campaign attacked Obama in a new ad out on Monday for giving a $535-million federal loan guarantee to solar panel maker Solyndra which later failed.

“Obama is giving taxpayer money to big donors. And then watching them lose it,” the ad says.

INITIAL ROUND OF ATTACKS

Romney, who lost the Republican presidential nomination to Senator John McCain in 2008, appears to have withstood an initial round of attacks from the Obama team over Romney’s work at Bain, which bought and restructured companies, sometimes resulting in a loss of jobs but generally earning Bain hefty profits.

“We feel that the president’s message is backfiring and his attacks on free enterprise and Governor Romney’s record in the private sector are embarrassing him and his campaign,” said Romney campaign spokesman Ryan Williams.

The Obama camp is using Bain to try to undermine Romney’s main argument for why he has the savvy to take on the economy – his business record.

“The job of a president is to lay the foundation for strong and sustainable broad-based growth – not one where a small group of speculators are cashing in on short-term gains. It’s to make sure that everybody in this country gets a fair shake,” Obama told supporters in Iowa last week. DM

Photo: Mitt Romney, U.S. Republican presidential candidate and former Massachusetts governor, shakes hands with supporters during a memorial day ceremony held at the Veterans Museum & Memorial Center in San Diego, California May 28, 2012. REUTERS/Denis Poroy