WASHINGTON — Al Franken became a senator on Tuesday, completing the transformation from comedian to politician.

The Minnesota Democrat's swearing-in marked the end of an eight-month political and legal struggle and drew thunderous applause and a standing ovation in the Senate chamber. His presence gives Democrats 60 votes, enough to thwart possible Republican filibusters.

Vice President Joe Biden administered Franken's oath, slapping the former Saturday Night Live performer on the back, then embracing him in a full hug. Former Vice President Walter Mondale, a Minnesota native, accompanied Franken. Franken was introduced by fellow Minnesotan and Democrat Sen. Amy Klobuchar.

"I think it was Al who told me that the third year of his campaign would be the best," Klobuchar said. "He was right."

Franken arrives in the Senate more than eight months after Election Day. Last week the Minnesota Supreme Court unanimously ruled in Franken's favor after a protracted recount and his opponent, former Republican Sen. Norm Coleman, conceded.

In the usually staid Senate, there were plenty of signs something unusual was afoot. The Senate Gallery, rarely full even with dozens of summer tours, was packed with onlookers. After Franken took the oath of the Senate, the gallery erupted in an unusual and lengthy applause that continued for several minutes.

Before the swearing in, Franken learned one truism of the Senate: nothing ever runs quite on time. Several senators read lengthy remarks from a Homeland Security bill as anticipation built for Franken's arrival. Franni Franken, the candidate's wife, smiled broadly and seemed to shift nervously in her seat.

Then, about 15 minutes later than had been scheduled, Klobuchar began her introduction. She said Franken would be a champion of average Minnesotans and played up his middle-class bona fides.

"He's demonstrated to Minnesotans that he takes his new job seriously," she said.

She added that he carried, "the same passion as Paul Wellstone," who was famous for his populist roots. Franken took the oath on a Bible that belonged to the family of the late Sen. Paul Wellstone, D-Minn.

Franken exchanged hugs with most of his Democratic colleagues and Vermont Sen. Bernie Sanders, an independent.

He acknowledged a section of the Senate Gallery that included Franken's wife, Franni. Franken waved to his wife and children while behind him his friend Sen. Tom Harkin, D-Iowa, gestured with his hands to raise the roof, prompting a fresh burst of cheers.