On January 29, 2007, Franken announced his departure from Air America Radio, and on the day of his final show, February 14, he formally announced his candidacy for the United States Senate from Minnesota in 2008.
Challenging him for the Democratic–Farmer–Labor Party endorsement was Jack Nelson-Pallmeyer, a professor, author, and activist; trial lawyer Mike Ciresi; and attorney and human rights activist Jim Cohen, who dropped out of the race early.
Franken won the nomination with 65% of the vote.

On July 8, 2007, Franken's campaign stated that it expected to announce that he had raised more money than his Republican opponent, Norm Coleman, during the second quarter of the year, taking in $1.9 million to Coleman's $1.6 million, although in early July 2007, Coleman's $3.8 million cash on hand exceeded Franken's $2 million.

In May 2008, the Minnesota Republican Party released a letter about an article Franken had written for Playboy magazine in 2000 titled "Porn-O-Rama!"
The letter, signed by six prominent GOP women, including a state senator and state representative, called on Franken to apologize for what they called a "demeaning and degrading" article.
His campaign spokesman responded, "Al had a long career as a satirist.
But he understands the difference between what you say as a satirist and what you do as a senator.
And as a Senator, Norm Coleman has disrespected the people of Minnesota by putting the Exxons and Halliburtons ahead of working families.
And there's nothing funny about that."

On June 7, 2008, Franken was endorsed by the DFL.
In a July 2008 interview with CNN, he was endorsed by Ben Stein, a noted entertainer, speechwriter, lawyer and author known for his conservative views, who generally supported Republican candidates.
Stein said of Franken, "He is my pal, and he is a really, really capable smart guy.
I don't agree with all of his positions, but he is a very impressive guy, and I think he should be in the Senate."

During his campaign, Franken was criticized for advising SNL creator Lorne Michaels on a political sketch ridiculing Senator John McCain's ads attacking Barack Obama in the 2008 presidential election.
Coleman's campaign reacted, saying, "Once again, he proves he's more interested in entertainment than service, and ridiculing those with whom he disagrees."

Preliminary reports on election night, November 4, were that Coleman was leading by over 700 votes, but the official results, certified on November 18, 2008, had Coleman leading by only 215 votes.
As the two candidates were separated by less than 0.5 percent of the votes cast, the Minnesota Secretary of State, Mark Ritchie, authorized the automatic recount provided for in Minnesota election law.
In the recount, ballots and certifying materials were examined by hand, and candidates could file challenges to the legality of ballots or materials for inclusion or exclusion.
On January 5, 2009, the Minnesota State Canvassing Board certified the recounted vote totals, with Franken ahead by 225 votes.

On January 6, 2009, Coleman's campaign filed an election contest, which led to a trial before a three-judge panel.
The trial ended on April 7, when the panel ruled that 351 of 387 disputed absentee ballots were incorrectly rejected and ordered them counted.
Counting those ballots raised Franken's lead to 312 votes.
Coleman appealed to the Minnesota Supreme Court on April 20.
On April 24 the Minnesota Supreme Court agreed to hear the case.
Oral arguments were conducted on June 1.

On June 30, 2009, the Minnesota Supreme Court unanimously rejected Coleman's appeal and said that Franken was entitled to be certified as the winner.
Shortly after the court's decision, Coleman conceded.
Governor Tim Pawlenty signed Franken's election certificate that same evening.
On January 29, 2007, Franken announced his departure from Air America Radio, and on the day of his final show, February 14, he formally announced his candidacy for the United States Senate from Minnesota in 2008. Challenging him for the Democratic–Farmer–Labor Party endorsement was Jack Nelson-Pallmeyer, a professor, author, and activist; trial lawyer Mike Ciresi; and attorney and human rights activist Jim Cohen, who dropped out of the race early. Franken won the nomination with 65% of the vote.
On July 8, 2007, Franken's campaign stated that it expected to announce that he had raised more money than his Republican opponent, Norm Coleman, during the second quarter of the year, taking in $1.9 million to Coleman's $1.6 million, although in early July 2007, Coleman's $3.8 million cash on hand exceeded Franken's $2 million.
In May 2008, the Minnesota Republican Party released a letter about an article Franken had written for Playboy magazine in 2000 titled "Porn-O-Rama!" The letter, signed by six prominent GOP women, including a state senator and state representative, called on Franken to apologize for what they called a "demeaning and degrading" article. His campaign spokesman responded, "Al had a long career as a satirist. But he understands the difference between what you say as a satirist and what you do as a senator. And as a Senator, Norm Coleman has disrespected the people of Minnesota by putting the Exxons and Halliburtons ahead of working families. And there's nothing funny about that."
On June 7, 2008, Franken was endorsed by the DFL. In a July 2008 interview with CNN, he was endorsed by Ben Stein, a noted entertainer, speechwriter, lawyer and author known for his conservative views, who generally supported Republican candidates. Stein said of Franken, "He is my pal, and he is a really, really capable smart guy. I don't agree with all of his positions, but he is a very impressive guy, and I think he should be in the Senate."
During his campaign, Franken was criticized for advising SNL creator Lorne Michaels on a political sketch ridiculing Senator John McCain's ads attacking Barack Obama in the 2008 presidential election. Coleman's campaign reacted, saying, "Once again, he proves he's more interested in entertainment than service, and ridiculing those with whom he disagrees."
Preliminary reports on election night, November 4, were that Coleman was leading by over 700 votes, but the official results, certified on November 18, 2008, had Coleman leading by only 215 votes. As the two candidates were separated by less than 0.5 percent of the votes cast, the Minnesota Secretary of State, Mark Ritchie, authorized the automatic recount provided for in Minnesota election law. In the recount, ballots and certifying materials were examined by hand, and candidates could file challenges to the legality of ballots or materials for inclusion or exclusion. On January 5, 2009, the Minnesota State Canvassing Board certified the recounted vote totals, with Franken ahead by 225 votes.
On January 6, 2009, Coleman's campaign filed an election contest, which led to a trial before a three-judge panel. The trial ended on April 7, when the panel ruled that 351 of 387 disputed absentee ballots were incorrectly rejected and ordered them counted. Counting those ballots raised Franken's lead to 312 votes. Coleman appealed to the Minnesota Supreme Court on April 20. On April 24 the Minnesota Supreme Court agreed to hear the case. Oral arguments were conducted on June 1.
On June 30, 2009, the Minnesota Supreme Court unanimously rejected Coleman's appeal and said that Franken was entitled to be certified as the winner. Shortly after the court's decision, Coleman conceded. Governor Tim Pawlenty signed Franken's election certificate that same evening.
Al Franken