Recharged Romney goes for more wins
Front-running Republican presidential candidate Mitt Romney will this week battle for three more US states, hoping to build on the growing sense of inevitability that he will win the race to challenge President Barack Obama.
Despite his big back-to-back victories in Florida and Nevada, his three opponents are vowing to stay in the fight against increasing odds that they can overcome the former Massachusetts governor's powerful campaign organisation and a massive financial advantage.
Colorado, Minnesota and Maine hold caucuses this week.
Newt Gingrich, the former speaker of the House of Representatives, has been thrashed by nearly unprecedented negative television advertising from Romney supporters. He promised, nevertheless, to battle on to the party's national nominating convention in August.
He said his goal was to "find a series of victories which by the end of the Texas primary will leave us at parity" with Mr Romney by early April.
Rick Santorum, a former Pennsylvania senator, and Ron Paul also say they are determined to keep up the fight.
All three are banking on the support of the conservative Republican base that is suspicious of Mr Romney's political history, including former support for abortion and gay rights.
Mr Gingrich is hoping for a strong showing on March 6, the so-called "Super Tuesday," when 11 states hold Republican nominating contests, including several Southern states which the former Georgia congressman sees as friendly terrain.