KY-SEN 2004: Mongiardo wins by 2%
SD-SEN 2004: Daschle wins by 3%
LA-SEN 2004: Vitter gets 47% in first round, loses 51-49% to Chris John in runoff
NC-SEN 2004: Bowles wins by 0.5%
TN-SEN 2006: Ford wins by 1%
MN-SEN 2008: Franken wins by 2%, so he is thus seated on schedule
KY-SEN 2008: Lunsford wins by 1%
WI-SEN 2010: Feingold wins by 2%
PA-SEN 2010: Sestak wins by 2%
What happens afterwards?
For Sestak and Feingold, they would still be senators even if Trump won in 2016, and would be possible presidential contenders.
For 2008, if McConnell lost Cornyn or Thune would become the next majority leader. It would also be a big blow to Republicans to lose their own leader.
For 2006, if Ford won in 2006 he likely would have lost in 2012 provided his opponent wasn't an Akin/Mourdock/Angle.
For 2004, it would make it much easier for Democrats to win the Senate in 2006 and they would have had a supermajority even after Scott Brown won the special election (assuming Specter still switches parties).
Some other ones
IL-2010: Giannoulias wins
GA-2008: Martin takes down Chambliss
MS-2008 SPECIAL: Musgrove takes out Wicker
FL-SEN 2004: Castor wins
