Barack Obama easily swept Democratic presidential contests in three states on Saturday, striking the latest blows in a bruising back-and-forth battle with Hillary Clinton for the party's nomination.

Among Republicans, former Arkansas Governor Mike Huckabee won contests in Louisiana and Kansas over front-runner John McCain, highlighting conservative discontent with the Arizona senator two days after he essentially sewed up the nomination.

Obama scored decisive wins in Louisiana, Nebraska and Washington to gain a small dose of momentum in a deadlocked, state-by-state fight with Clinton for Democratic convention delegates who will choose the party's presidential nominee.

?Today, the voters from the West Coast to the Gulf Coast to the heart of America stood up to say yes, we can,? Obama said at a party dinner in Richmond, Virginia, a state that votes on to-morrow. ?We won in Louisiana, we won in Nebraska, we won in Washington state, we won North, we won South, we won in between, and I believe that we can win Virginia on Tuesday if you're ready to stand for change,? the Illinois senator said.

The wins by Huckabee, a Baptist minister whose campaign has been fueled by support from religious conservatives, came in states with big conservative voting blocs and did not change McCain's daunting advantage in the Republican race.

McCain has more than 700 of the 1,191 delegates needed to capture the Republican nomination at this summer's convention. He virtually clinched the race on Thursday with the withdrawal of his chief rival, former Massachusetts Governor Mitt Romney.

But Huckabee said he would not give up, telling a conference of conservative activists in Washington he would continue his shoestring campaign until McCain mathematically won the nomination. McCain still faces widespread opposition from conservatives unhappy with his views on immigration, tax cuts and other issues. ?I did not major in math, but I majored in miracles, and I still believe in them,? Huckabee said at a rally at the University of Maryland in College Park.

McCain held a slim lead on Huckabee in Washington state with nearly 90 percent of the vote counted late Saturday. Huckabee won about 60 percent of the vote in Kansas, more than double McCain's total. He narrowly beat McCain in Louisiana.

Easy wins

Obama cruised to easy wins in Nebraska and Washington, doubling Clinton's tally by capturing more than 60 percent of the vote. He comfortably beat Clinton in Louisiana, winning more than half of the vote. Obama also won easily in the US territory of the Virgin Islands.

Clinton, a New York senator, and Obama are about even in pledged delegates after contests in more than half of the US states, but both are well short of the 2,025 needed to win the nomination.

Democratic rules allocate delegates on a proportional basis statewide and in congressional districts, meaning even the loser in each state can win big blocks of delegates. There also are another 796 ?super-delegates?, elected officials and party insiders, who can switch their support at any time.

Obama, who would be the first black US president, had been the favorite in all three contests. In Louisiana, he benefited from a high percentage of black voters, his strongest supporters.

Obama and Clinton have squared off again yesterday in Maine, a caucus state, before they head into Tuesday's round of contests in Virginia, Maryland and the District of Columbia.

John WHITESIDES