Daily Fix Poll: What was the biggest upset of the 2010 primary season?

By Aaron Blake

The 2010 primary season ends this week, and it could close with a bang if Christine O'Donnell upsets Rep. Mike Castle in the Delaware GOP Senate fight tonight.

Most analysts agree that an O'Donnell win would be the biggest upset of the cycle to date; Castle is popular longtime statewide officeholder, while O'Donnell is a conservative tea party candidate with plenty of baggage and very little money or campaign organization.

Pondering an O'Donnell victory got us to thinking about the other major upsets of the 2010 primary season and which ranked as the biggest surprise. So as we wait for the votes to trickle in on this final big primary day, we ask you to look back and tell us: What was the most surprising primary result to you?