Victory in Texas primary means Mitt Romney will run against Barack Obama but Trump's 'birther' fixation taints moment
Mitt Romney has clinched the Republican presidential nomination with a resounding victory in Texas and now faces a five-month sprint to convince voters to trust him over President Barack Obama in the 6 November election.
The race has been effectively over for weeks but Romney finally cleared the benchmark of 1,144 delegates needed to become the Republicans' presidential candidate after a long, bitter primary battle.
He will be formally nominated at the Republican convention in Florida in late August. Romney said he was humbled to win enough of Texas's 155 delegates to secure the nomination. "Our party has come together with the goal of putting the failures of the last three and a half years behind us. 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's big day was overshadowed by his appearance with the real estate tycoon and reality TV star Donald Trump, who organised a major fundraiser for Romney in Las Vegas. A famous self-promoter, Trump has been loudly fixated over whether Obama was born in the United States despite clear evidence that he was born in Hawaii, and Romney did nothing to publicly rein him in.
Romney endured serious threats from Republican opponents, such as Rick Perry and Rick Santorum, to reach a goal that his late father, the former Michigan governor George Romney, fell short of achieving: winning his party's stamp of approval as its presidential candidate.
It is always difficult to unseat an incumbent president and Romney is considered the underdog. But with the economy staggering along, polls are close.
All indications are that Americans face the possibility of a cliffhanger election in November that will be decided by relatively small percentages of voters in as many as a dozen battleground states, such as Ohio, Florida and Virginia.
The former Massachusetts governor has a lengthy to-do list ahead of his duel with Obama, from picking a vice-presidential running mate to raising hundreds of millions of dollars for a national campaign.
In the immediate weeks ahead his goal is to bolster his case that Obama has been ineffective in handling the sluggish US economy and hostile to job creators. This argument will extend to the energy industry, which Romney thinks Obama has bungled by not ramping up domestic production of oil and natural gas.
Romney has vowed to repeal the Obama's 2010 healthcare overhaul if elected, citing it as an example of too much government under the Democratic president. He has faced criticism from Republicans for the healthcare overhaul he developed for Massachusetts that Obama has called a model for revamping the US system.
Romney is popular with white men and military veterans but needs to bolster his popularity among women and Hispanics, two key voting blocs.
Trump in recent days has resurrected the issue of Obama's birth certificate to raise questions about whether the president meets the constitutional requirement of being a natural-born citizen of the United States. The topic had seemed to run out of steam a year ago when the White House produced the president's detailed "certificate of live birth" from Hawaii, but Trump has told CNN he is not convinced of the document's authenticity.
Obama's re-election campaign eagerly lumped Romney in with Trump and the fringe "birther" movement to try to damage the Republican's standing with independent voters who are likely to decide the election.
Romney himself did not address the issue head-on, refusing to condemn Trump but issuing a statement saying he believes Obama was born in the United States.
Winning the nomination 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.