Will Republicans or Democrats win the Senate? These key midterm races will decide.

Control of both chambers of Congress is up for grabs in November's election. But as important as the House of Representatives is, all signs point to the true drama of the midterms being in the battle for the Senate. There are 35 Senate seats on the ballot this year. Most of those races won't be competitive. The balance of power in the Senate will be decided by the dozen or so states where the outcome truly is uncertain. Republicans currently hold a 53-47 majority, which means they can lose