Mitt Romney clinches GOP nomination

WASHINGTON -- Mitt Romney clinched the Republican presidential nomination Tuesday with a win in the Texas primary, a triumph of endurance for a candidate who came up short four years ago and had to fight hard this year as voters flirted with a carousel of GOP rivals.

According to the Associated Press count, Romney surpassed the 1,144 delegates needed to win the nomination by winning at least 88 delegates in the Texas primary.

The former Massachusetts governor has reached the nomination milestone with a steady message of concern about the U.S. economy, a campaign organization that dwarfed those of his GOP foes and a fundraising operation second only to that of his Democratic opponent in the general election, President Barack Obama.

"I am honored that Americans across the country have given their support to my candidacy and I am humbled to have won enough delegates to become the Republican Party's 2012 presidential nominee," Romney said in a statement.

"Our party has come together with the goal of putting the failures of the last three and a half years behind us," Romney said. "I have no illusions about the difficulties of the task before us. But whatever challenges lie ahead, we will settle for nothing less than getting America back on the path to full employment and prosperity."

Romney must now fire up conservatives who still doubt him, while persuading swing voters that he can do a better job fixing the nation's struggling economy than Obama. In Obama, he faces a well-funded candidate with a proven campaign team in an election that will be heavily influenced by the economy.

"It's these economic indicators that will more or less trump any good or bad that Romney potentially got out of primary season," said Josh Putnam, an assistant political science professor at Davidson College who writes the political blog Frontloading HQ.

Republicans won't officially nominate Romney until late August at the GOP national convention in Tampa, Fla. Romney has 1,174 convention delegates.

He won at least 88 delegates in Texas with 64 left to be decided, according to early returns. The 152 delegates in Texas are awarded in proportion to the statewide vote.