Path cleared for Romney

Rick Santorum suspended his campaign for the Republican presidential nomination yesterday, leaving the field clear for Mitt Romney as the party's likely choice to challenge President Barack Obama in November.

The former Pennsylvania senator made the announcement in his home state two weeks before the Republican primary vote there.

Santorum was trailing Romney in polls in Pennsylvania. He had earlier said the state was a must-win to keep his candidacy alive.

"This race is over for me," Santorum told supporters.

Santorum was a favourite of the most conservative Republican voters, but Romney, the former Massachusetts governor, had accumulated a huge lead in delegates to the party's national convention in August.

Santorum pointedly made no mention or endorsement of Romney, whom he had derided as an unworthy standard-bearer for the Republicans.

Romney congratulated Santorum on his campaign, calling him an "able and worthy competitor".

The conservative Republican base is suspicious of Romney's credentials, but Santorum's inability to put together primary election victories in key states - especially in the industrial Midwest - appeared to have convinced most voters that Romney's nomination was inevitable.

Santorum was the only Republican, in what started out as a crowded field, who was able to create a sustained challenge to Romney, who is making his second run for the nomination.

The distaste that conservatives felt for Romney showed itself in a series of runs at his front-runner status by Republican Michelle Bachmann, Texas governor Rick Perry, businessman Herman Cain and former House of Representatives speaker Newt Gingrich.

Gingrich yesterday said he would stay in the race until the party's convention.

Obama stepped up his election year with the insistence that the wealthy must pay a greater share of taxes .

Hoping to draw a sharp contrast with Romney, Obama outlined his support for the so-called "Buffett rule", named after billionaire investor Warren Buffett, who famously said it was wrong for him to be paying a lower tax rate than that levied on his secretary.

Obama has proposed that people earning at least $1-million annually should pay at least 30% of their income in taxes.

The White House said in a report released ahead of Obama's speech that the tax proposal would restore fairness to the system.

Romney's campaign spokesman, Gail Gitcho, said Obama was the "first president in history to openly campaign for re-election on a platform of higher taxes".