Mitt Romney all but secured the Republican nomination after Rick Santorum suspended a tenacious shoestring campaign, paring down the US presidential race to two clear choices.

A charismatic Democratic president, vulnerable to any sign that the tentative economic upswing might stall, faces off against a multimillionaire who has struggled to connect with his own party's conservatives but hopes his business background will convince voters he can put the country on a path to sturdier recovery.

Now Romney and President Barack Obama are free to focus on confronting each other, something they had already been increasingly doing in recent weeks as the former Massachusetts governor gradually emerged as his party's likely nominee.

Neither has hesitated to draw sharp contrasts with the other.

Obama, whose re-election prospects have been buoyed by the divisive state-by-state Republican primary race, said the choice facing voters this November was one of the starkest in recent history.

Traveling to Florida, Obama opened a new push to revamp the US tax law under which wealthy investors often pay taxes at a lower rate than middle-class wage-earner. The proposal stands little chance of passing in Congress but serves as a clear general election contrast with Romney.

"We've got to choose which direction we want this country to go," Obama told a boisterous audience of students at Florida Atlantic University.

【Romney in control after Santorum bows out】相关文章：

★ People in your life

★ Urbanites suffer anxiety going home

★ Comic collection could yield serious money

★ Obama, Lee warn DPRK rocket test

★ Blood-lead level testing resumed amid outcry

★ Honduras prison fire kills at least 357

★ Shenzhen cops accidentally shoot cabbie

★ Police issue warrant for former Maldives president

★ Cuisine lexicon offers tasty food for thought

★ Half of cooked meat tested substandard