Sen. Barack Obama (D-IL) handily defeated Sen. Hillary Clinton (D-NY) in all four Democratic nominating races Saturday. Voters in Louisiana , Nebraska, Washington state and the U.S. Virgin Islands overwhelmingly chose the Illinois senator, further tightening the race for Democratic delegates between Obama and Clinton.

In his victory speech at the Virginia Jefferson-Jackson dinner Saturday night, Obama repeated his pokes at Clinton that if he is the Democratic nominee, Sen. John McCain (R-AZ) “will not be able to say that I agreed with him on voting for the war in Iraq; agreed with him on giving George Bush the benefit of the doubt on Iran; and agree with him in embracing the Bush-Cheney policy of not talking to leaders we don’t like.” Clinton also spoke at the event, but did not mention Obama, instead attacking McCain on economic issues and his support for the war in Iraq.

The economy was the top voting issue for Louisiana Democrats, according to exit polls (AP). About 30 percent of voters said the war in Iraq is the most important issue facing the country. Louisiana voters, still struggling to rebuild more than two years after Hurricane Katrina, largely supported Obama (CNN).

Exit poll data from Washington state and Nebraska was not immediately available.

In a much closer contest than the Democratic primaries Saturday, McCain won the Washington state Republican primary by a small margin. In Kansas , on the other hand, former Arkansas Governor Mike Huckabee won about 60 percent of the vote (Reuters). Huckabee also won by a small margin in Louisiana. GOP voters in Louisiana picked the economy as the top issue facing the country, while Iraq, illegal immigration and terrorism were each named by 20 percent of voters. Huckabee got the most votes from Republican voters listing the economy and terrorism as the most important issues, while those most concerned about Iraq chose McCain. Voters naming illegal immigration as the most pressing issue were divided evenly between the two candidates, according to exit polls.