The Indiana Republican Senate primary on Tuesday may mark the end of longtime incumbent Dick Lugar’s career.State Treasurer Richard Mourdock has a 10-point lead over the six-term Senator in the latest independent poll and could be one of the biggest upsets in primary history. However, polls also show Mourdock tied with the Democratic candidate, Congressman Joe Donnelly, who is unopposed in his election.Mourdock is a Tea Party favorite who ran well to the right of Lugar. Indiana Democratic Party Chairman Dan Parker says voters will take note of that in the fall election. "He is way to the extreme in Indiana. He’s going to try to rebrand himself, but the reality is that Richard Mourdock is the tea party candidate and Joe Donnelly is a moderate Democrat who is sitting in the middle of the electorate where most Hoosiers sit," he says. "And we look forward to that contest and Richard Mourdock makes decision based on ideology, on strident ideology."Super PACs have spent a total of $4.5 million on the GOP primary, which is the most on any congressional race this season.The GOP needs to pick up four seats to take back the Senate, and many strategists were counting on the GOP winning Indiana's seat. The Indiana Republican Party could not be reach for comment.