Over 9,000 Democrats are expected in Des Moines tonight for one of the year’s biggest political events.  Four years ago — in November of 2003 — the Iowa Democratic Party’s annual Jefferson-Jackson Day Dinner marked a turning point in John Kerry’s campaign. He took the center stage and declared, “bring it on.” Hillary Clinton was that night’s emcee.

Tonight, Clinton will be back as one of the six presidential candidates who’ve been told they each have 10 minutes to speak to the crowd. Two of the candidates suffered stumbles Friday on the eve of the big event. The Clinton campaign acknowledged it had planted a question for Clinton at an event in Newton earlier this week.

A Grinnell College student revealed to a reporter for her college newspaper that someone from the Clinton campaign approached her and said she should be ready to ask Clinton about global warming. The Clinton campaign statement issued Friday night said it is “not standard policy” to stage questions for Clinton and the practice “will not be repeated.”

The other candidate misstep? John Edwards appeared briefly on-stage with musician and friend John Mellencamp in Des Moines last night and the crowd erupted in boos. Edwards often plays the Mellencamp tune “Small Town” at campaign events and Mellencamp had just played the tune for the crowd before Edwards’ appearance.