Delaware Senate GOP Primary 2010: Who Will Win? (PREDICT)

09/14/2010 05:30 pm ET | Updated May 25, 2011

Tonight's Delaware GOP Senate primary will be a race to watch closely.

A new poll shows that the contest between Us. Rep. Mike Castle (R-Del) and Tea Party-backed challenger Christine O'Donnell is "too close to call" heading into Tuesday's primary election.

Just yesterday, Delaware GOP Chairman Tom Ross was reportedly threatened with "a bullet in the head" for supporting Castle over O'Donnell.

New Jersey Gov. Chris Christie, a big Republican name, also endorsed Castle in his primary fight.

O'Donnell is running with the backing of the Tea Party Express and the prospect of her candidacy has the GOP "spooked."

Who do you think will prevail in the Castle-O'Donnell showdown? Share your prediction below and check back here for results later.