CHICAGO - Minnesota's Supreme Court ruled Tuesday that comic Al Franken is the winner in a bitter US Senate race, a step that could hand Democrats sweeping powers to pass US President Barack Obama's agenda.

The unanimous decision could notably have far-reaching implications for Obama's push to approve legislation to fight climate change, reform US health care, and win Judge Sonia Sotomayor's confirmation to the US Supreme Court.

Should Franken be seated, Democrats and their two reliable independent allies would have the 60 Senate votes needed to break through any Republican efforts to use a parliamentary delay tactic called a filibuster.

Obama's Democratic allies already enjoy a robust majority in the US House of Representatives, so a filibuster-proof Senate majority would deal a sharp blow to Republican efforts to block or force changes to major legislation.

Republicans looking to derail or modify Obama-backed legislation would likely target a handful of swing-vote Democrats who have indicated discomfort with some of the president's plans.

Democratic Senate Majority Leader Harry Reid said in a statement he hoped to seat Franken "as soon as possible" and urged Minnesota's Republican governor, Tim Pawlenty, to sign the formal document certifying that the Democrat won.

A spokesman for Reid said Franken would not be seated before next week - the Senate is in recess for the July 4 US independence day holiday.

Franken, who rose to fame on the legendary Saturday Night Live program, has been locked in a months-long legal battle over the validity of the November 4 election after a series of recounts handed him a victory of just 312 votes.

Republican incumbent Norm Coleman, who challenged the fairness of the election and the accuracy of the recount, still has the opportunity to appeal the decision to the US Supreme Court.

However, Pawlenty has said he will issue a certificate granting Franken the seat should the state's highest court rule in his favor.

In a unanimous opinion, the court ruled that "Al Franken received the highest number of votes legally cast and is entitled under Minnesota statute... to receive the certificate of election as United States Senator from the State of Minnesota."