Voters in Indiana, North Carolina and West Virginia are heading to the polls to cast their primary ballots.  There's one race - not for President - in Indiana that's tighter than most.

FOX News Radio's Jennifer Keiper reports from the Hoosier State:

It's one of Indiana's most expensive Senate primaries: incumbent Dick Lugar and State Treasurer Richard Mourdock are battling it out, with both candidates spending millions on advertising, a lot of it negative.  Lugar has been plagued by residency issues and Mourdock's campaign manager got into some hot water over how a party database was used.

This had been a close race, the Lugar camp saying...

(Lugar Spokesman) "That is not, uh, a surprise."

But a recent Howey-Depauw polls shows Lugar trailing Mourdock 48%-38%.  Mourdock's team has said...

(Mourdock Spokesman) "I think people are willing to give another candidate a try."

Mourdock, the State Treasure, has been getting a lot of help from the Tea Party.

Jennifer Keiper, FOX News Radio.