There isn't one.
Tomorrow is primary election day in Indiana but, after incumbent Democratic Senator Evan Bayh abandoned his reelection campaign, the filing deadline came and went, with no other Democrat qualifying to get on the primary ballot. Therefore, the Indiana Democrats' central committee will choose a nominee.
That group is virtually certain to select Congressman Brad Ellsworth, 51, who has represented an Evansville-area district in the U.S. House since 2007. In the Democrats' 2006 landslide, Ellsworth defeated six-term Republican incumbent John Hostettler, who is a candidate in the Republican primary to nominate Ellsworth's opponent in this Senate race.
Ellsworth had previously worked in law enforcement, having been a sheriff at the time of his election to Congress.
Republicans accused Bayh of timing his withdrawal announcement so as to guarantee that party insiders could choose the Democratic nominee, and avoid a primary.