Since President Obama took office, Republicans have squandered a litany of winnable Senate races because a hard-fought primary left them with a damaged — or outright unelectable — nominee.
In 2016, it might be the Democrats' turn to shoot themselves in the foot.
In a quartet of key battlegrounds, Democrats are bracing for bitter primaries that party leaders worry will complicate their hopes of retaking a Senate majority. The latest showdown was set Tuesday, when a former top aide to Pennsylvania Gov. Tom Wolf, Katie McGinty, declared she would seek the party's nomination for Senate in a race that already includes former congressman and 2010 nominee Joe Sestak.
The Pennsylvania race joins a list of intraparty showdowns that already includes Ohio, where former Gov. Ted Strickland is trying to fend off a young city councilman from Cincinnati, and Illinois, where Rep. Tammy Duckworth faces the former president of the Chicago Urban League. In Florida, the most high-profile fight of all awaits, when outspoken Rep. Alan Grayson takes on Rep. Patrick Murphy.
The bevy of primaries is a relatively new phenomenon for Democrats, who have escaped most recent election cycles with nary a serious fight in a state considered a general-election battleground — and it has left leading operatives scrambling to devise a strategy to make sure the strongest possible nominee reaches the general election. The fights have also left Republicans sensing opportunity to help their own chances of holding onto a majority.