Democrats' red state blues are a big deal considering Democrats have to defend seven seats more Republican than the nation as a whole, while Republicans only have to beat back a Democratic challenge in one state won by President Obama. Seven minus one equals the six seats the Republicans need for control.
Yet, I would argue that 2014 recruitment failures are as much about the current state of each party's coalitions than anything particular to this election cycle. There are now more states that lean Republican than lean Democratic. Twenty-six states are more Republican than the nation as a whole. Only 23 states are more Democratic. Virginia votes with the nation. Translating that to Senate seats, we'd expect something like a 53 to 47 Republican advantage on presidential vote alone.
Just twenty years ago, this Republican state edge might not have been so big of a deal. In 1993, 49% of the Senate Democratic caucus came from red states, and 28% of the Republican caucus came from blue states.
Now though, straight-ticket voting is becoming the rule for senate elections. Only 25% of the Democratic Senate caucus comes from red states, while 16% of Republicans come from blue states. The 25% and 16% listed above should fall even further as Republicans bump up their numbers with red staters in 2014, while the Democratic caucus will become more limited to blue staters.
These statistics explain why Democrats are having such recruitment problems in red states in 2014, and why they should for years going forward. People don't want to run in races they'll probably lose.