Mike Huckabee wins Kansas caucuses

Republican White House hopeful Mike Huckabee got a boost to his lagging campaign for the party's presidential nomination when he won the Kansas caucuses, US media said.

With 79 per cent of precincts reporting, the ordained Baptist preacher was winning with 62 per cent of the vote compared with 22 per cent for Republican front-runner John McCain, CNN and Fox television news channels said.

Huckabee, 52, has put up a David-and-Goliath fight against veteran politician McCain, with his populist message proving a winner in the country's many more rural, conservative states.

McCain, 71, is all but guaranteed the Republican nomination after former Massachusetts governor Mitt Romney pulled out of the race on Wednesday.

But he has yet to convince the party's core conservatives that he is the best candidate, after enraging them with his stands on illegal immigration and finance reforms.