Democrats are playing defense in some key U.S. Senate races that should otherwise be considered safe.

Historically, Senate incumbents already tend to be a bit less safe than House incumbents simply because one cannot gerrymander a state. House lines are often drawn and redrawn to protect incumbents, while states don't change borders without something major...like a war. Even in that revolutionary year of 1994, 92% of House members seeking re-election won, while 90% of Senators won.

A review of the position some incumbent Democrat Senators find themselves in shows a level of vulnerability that is out of the ordinary, and certainly a far cry from the last two election cycles which saw heavy Democrat gains.

Complete story on Fox and Hounds Daily