A question about the Minnesota Senate race

From Monday's WSJ.com's Political Diary:

New Mexico Senator Tom Udall: "I remember asking about it, and was told not to worry about it because we'd have 60 votes once Al Franken got seated. Well, we found out what 60 votes got us."

I have one question: why were the Democrats so certain in December 2009 that Franken would be declared the winner. Wasn't Senator Norm Coleman still in the lead at that time?