WASHINGTON -- WASHINGTON — Al Franken's victory in the long-contested Minnesota U.S. Senate race means that Democrats will control 60 Senate seats for the first time in 30 years, but they'll still face obstacles to passing major legislation.

On paper, the party now has the muscle to block any Republican filibuster, since it takes 60 votes under Senate rules to end debate and move to a final vote. However, two key Democratic senators are battling serious illnesses, two others are independents who caucus with the party but aren't sure votes with the majority, and all senators have diverse constituencies that sometimes lead them to break ranks with their parties.

As a result, it's unlikely that the 58-year-old Harvard-educated comedian and now senator-elect will make a dramatic difference this year as his party and the White House fight to overhaul health care, limit carbon emissions and pass other major legislation.

"It's a numerical achievement, but not necessarily a political one," said Ross Baker, a political science professor at Rutgers University.

Franken's eight-month quest to become Minnesota's junior senator ended Tuesday when the Minnesota Supreme Court unanimously rejected Republican incumbent Norm Coleman's challenge.

"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," the court ruled.

Coleman conceded soon afterward. First elected in 2002, he seemed at ease during a news conference outside his St. Paul home.

"Sure, I wanted to win. I thought we had a better case, but the court has spoken," Coleman said. He called Tuesday "a time to look forward and not backward," but wouldn't discuss a possible 2010 governor's race.

Franken, one-time star and writer on NBC's "Saturday Night Live," dismissed talk about his status as the 60th Democratic vote.

"That's not how I see it," he said. "The way I see it, I'm not going to Washington to be the 60th Democratic senator, I'm going to Washington to be the second senator from Minnesota, and that's how I'm going to do this job."

Franken, who said he had a "very gracious call" Tuesday from Coleman, is expected to be seated next week when the Senate returns from its Fourth of July recess. He said he'd join the Health committee, which is writing health care legislation, and the Judiciary Committee, which will begin hearings on the nomination of federal appellate Judge Sonia Sotomayor to the U.S. Supreme Court on July 13.

Democrats will still face obstacles in getting 60 votes, however. Ailing Sens. Robert Byrd of West Virginia and Edward Kennedy of Massachusetts have been absent frequently.

Vermont's Bernard Sanders and Connecticut's Joseph Lieberman are independents who are counted as part of the Democratic caucus, but Sanders is considered more liberal than most Democrats and Lieberman is more allied with Republicans on national security issues.

Amassing 60 votes also will depend on the issue. When climate change legislation came up in the House of Representatives last week, 44 Democrats voted no on the party plan and Republican votes were needed to pass it.

In the Senate, that bill's "going to need 60 votes to stop a filibuster, and you can easily name 10 or 15 Democrats who aren't going to vote for a bill at all," said Steven Schier, a political science professor at Carleton College in Northfield, Minn.