Senate election timeline

The lead in the U.S. Senate election changed hands only once. Norm Coleman's election night margin gradually dwindled, while the lead Al Franken took in mid-December has held firm and grown. Here's how the numbers and situations have shifted:

Nov. 4: Election Day. Race between Republican Sen. Norm Coleman and DFLer Al Franken is too close to call. Coleman's lead, in the early morning hours of of Nov. 5, is 725 votes.

Nov. 5 (evening): As county officials review vote counts, Coleman's margin shrinks.

Nov. 18: With counties having certified results, Coleman has a 215-vote lead. The margin, less than 1/100th of 1 percent, triggers a recount that starts the next day.

Dec. 5: Hand recounting of ballots ends with Coleman up by 192, but several thousand have been "challenged" by the campaigns -- that is, the counter's decision has been disputed. The ballots will be reviewed by the state Canvassing Board, which will make the all-important final decisions.

Dec. 18: State Supreme Court rules 3-2 that improperly rejected absentee ballots should be identified and counted. The ruling requires both campaigns plus local election officials to agree that a ballot was wrongly disqualified for it to be accepted. Franken has been seeking to have such ballots added to the mix, while Coleman has been opposed, saying the matter is beyond the scope of a recount and something to be addressed in a legal challenge.

Dec. 19: After the Canvassing Board spends several days reviewing disputed ballots, Coleman's long-held lead disappears and Franken jumps ahead for the first time.

Jan. 3: The secretary of state's office counts 933 absentee ballots that the campaigns agree were wrongly rejected. Franken's lead grows to 225 votes, a result the Canvassing Board certifies two days later.

Jan. 6: Coleman files a lawsuit challenging the results. Much of his case involves trying to get more rejected absentee ballots counted. Franken defends the state's strict requirements for absentee ballots.

Feb. 13: The judicial panel hearing the lawsuit issues a ruling on which categories of rejected absentee ballots can be admitted. The Coleman camp later dubs it the "Friday the 13th" order, saying it is too restrictive and compounds a problem of similar ballots being treated differently.

April 7: Under the panel's ruling, 351 once-rejected ballots are counted, and Franken's lead grows to 312.

April 13: The panel issues a final trial ruling, saying Franken won.

April 28: In Washington, D.C., Pennsylvania Sen. Arlen Specter announces that he is switching from the Republican to the Democratic Party, heightening the stakes in Minnesota. With Specter's move, Franken stands to become the 60th Democratic vote in the Senate, a filibuster-proof majority -- if he wins.

June 1: Oral arguments are heard in Coleman's state Supreme Court appeal.