Growing up in New York, I recall an old commercial for the lottery that sought to sucker in the math-challenged by telling them 'you gotta be in it to win it.' While I still consider that an indefensible way for a state to get people to throw away their money, it's undoubtedly true when it comes to political campaigns. You may be unable to predict the political climate months before election day (or even days before). But if you hope to have any chance of winning seats that may be unexpectedly within reach, you have to have credible candidates. So far this cycle, it's the Republican campaign committees that are winning the race to find strong candidates for potentially-winnable races:
It's not just the Senate races, however. The National Republican Congressional Committee has announced sought-after candidates early and often. These include Martha Roby (Alabama's 2nd District), Van Tran (California 47th), Charles Djou (Hawaii 1st), Vaughn Ward (Idaho 1st), not to mention rematches in two races that would allow Republicans to recapture seats lost in 2008; Andy Harris vs. Freshman Rep. Frank Kratovil (Maryland 1st) and former Rep. Steve Chabot facing the man who defeated him, Rep. Steve Driehaus (Ohio 1st).
Nearly every day, either the NRSC or NRCC touts another Republican recruiting success or taunts another Democrat recruiting failure. Their Democratic counterparts, on the other hand, have had very little to say on the topic.
And with good reason—with the exception Tim Griffin declining to run in Arkansas and Kentucky Senator Jim Bunning's antagonizing of his party leadership, it's difficult to think of a prominent race where Democrats have outperformed Republican candidate recruitment. Yet Kentucky is hardly a perfect model for Democrats, as Lt. Gov. Daniel Mongiardo and state Attorney General Jack Conway are locked in divisive Democratic primary and many Republicans believe Bunning's truculence (and lack of fundraising) will eventually allow a more electable Republican to enter the campaign.
Meanwhile Democrats are lining up to challenge the three newest additions to the Senate Democratic Conference, Sens. Roland Burris, Kirsten Gillibrand, and Arlen Specter, in primaries that look to be crowded, expensive, and ugly. In these contests, even with Rep. Jan Schakowsky dropping out in Illinois, Democrats appear to be more eager to run against the newest Democratic senators than they do Republicans.
There are good reasons that the NRCC and NRSC are having more success in recruiting strong candidates. Chairmen Sessions and Cornyn have made it a top priority, for one thing. Both recognize for example, that strong candidates are a boon not just in winnable races, but also in longshot campaign and near-hopeless districts. You never know when lightning might strike and make a seemingly strong incumbent vulnerable to a credible challenger. And even in hopeless races, a strong candidate can force the Democrats to spend more time and money defending what ought to be 'safe seats.'
Furthermore, there are undoubtedly ambitious Republicans who have kept their powder dry the last few cycles, and waited for a better climate to run. The reverse is true for Democrats, who know they had their best chances in 2006 and 2008, and if they did not run in the last few cycles there may not be much reason to now.
Further, good recruiting can be part of a virtuous circle. Strong recruits help build confidence that a good year is ahead; that can aid both fundraising and other recruiting. Success begets success.
Lastly, getting good candidates early also forces Democrats to think about the future. Do you think Bill Foster (D-IL) is going to be as comfortable voting for an extreme liberal agenda now that he knows he's going to face a challenging candidate with huge name identification, in a Republican-leaning district? Multiply that effect for every marginal-seat Democrat who faces (or may face) a tough re-election challenge, and you have a Democrat majority that's much harder to manage.