(CBS News) WASHINGTON - The Republican presidential race is over.
Mitt Romney won the Texas primary Tuesday, picking up.
CBS News estimates Romney now has 1,198 GOP delegates.
Romney didn't go to Texas Tuesday night to celebrate.
He was raising big money with Donald Trump in Las Vegas.
Everything about Trump is big, including the money he can raise for political campaigns.
The question for Romney is whether Trump can also cause some big headaches with his big mouth.
Tuesday night in Las Vegas, Romney kept his focus on President Obama and the economy.
"He's been a big disappointment, hasn't he?" Romney asked a crowd.
"Yeah!" the crowd shouted.
The former Massachusetts governor was in the swing state of Nevada attending a $2 million fundraiser hosted by Trump, who's been raising money and bringing his celebrity to Romney's campaign.
But if raising money is what Trump does best, he's also good at stirring up controversy.
And so on Romney's day, there was the billionaire big-talker continuing to question, in a phone interview with CNN's Wolf Blitzer, whether Mr. Obama was born in the U.S.
"A lot of people do not think it was an authentic (birth) certificate (the president released)," Trump told Blitzer.
"How could you say that if the state..." Blitzer began to ask.
" ... Many people do not think it was authentic," Trump insisted.
It was Trump's questions last year that prompted Mr. Obama to release his full birth certificate, which the state of Hawaii recently gave its seal of approval.
Romney has said he believes the president was born in America, but he's hasn't disavowed Trump, saying he and his supporters aren't going to agree on everything.
And at Tuesday night's fundraiser, Newt Gingrich, a former rival-turned-new-supporter, came to Romney's defense, saying, "Governor Romney's not distracted. The Republican party's not distracted. We believe that this is an American-born job-killing president; other people may believe that he was born somewhere else and still kills jobs."
Also Tuesday night, Romney met with mega-donor Sheldon Adelson who, with his wife, gave $20 million to Gingrich - the kind of money the Romney campaign could certainly use going head-to-head with the president's re-election effort.