If you really think Greg Fischer or Bruce Lunsford is going to beat Sen. Mitch McConnell in November, you might want to look at Intrade.com.
A more Democratic Senate might get you free government healthcare, or nationalized oil companies (free gas, anyone?), or whatever.
But at a last trade of $17 for a contract on "any Dem beats Mitch," the prediction market presents an excellent opportunity for you (if you really believe!) to put someone else's money in your mouth.