The former Massachusetts governor won 71 percent of the vote in Texas, according to Fox News and CNN on its website, which reported his victory along with NBC television.
The projected victory should secure Romney the 1,144 delegates needed to become the party`s 2012 flag bearer to take on Democratic President Barack Obama in November.
Republican National Committee (RNC) chairman Reince Priebus hailed the victory, saying it paves the way for the party`s August convention in Tampa, Florida, where Romney will be formally nominated and reveal his running mate.
"I congratulate Governor Romney on winning the Texas primary and securing the delegates needed to be our party`s official nominee at our convention in Tampa," he said in a statement as quoted by AFP.
"Gov. Romney will offer America the new direction we so desperately need. We cannot afford four more years of President Obama`s big government agenda, deficit spending, and attacks on American free enterprise."
"At a time when the country must empower the private sector to create jobs, we need a leader who actually understands job creation and respects the private sector," he added.
Romney was the only Republican still actively campaigning in Texas, the second most populous US state, for the nomination to challenge Obama for the White House in November.
US congressman from Texas Ron Paul won 10 percent in his home state, Catholic conservative Rick Santorum 7 percent and former House Speaker Newt Gingrich 5 percent, according to CNN.
(C003)
Editor: Maryati
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