It's not just Republicans who are tussling. Democrats have some civil wars on their hands, too.
Four of 2014's top 10 primaries involve Democratic candidates. In one case, the party establishment is pitted against a leading women's group. In others, rising stars are in pitched battles. And one case is the latest iteration of a unique long-standing factional fight.
The good news for Democrats is that in most of these cases, the primary disunity does not put the party at risk of coughing up an otherwise winnable seat. It's been a different story for Republicans during the last couple of cycles. (See O'Donnell, Christine; Akin, Todd; Mourdock, Richard; and Buck, Ken). And this year, a contested primary in Georgia could be a difference-maker in the fight for the Senate majority.
Below is our rundown of the top 10 primaries, in alphabetical order. As a reminder, some races stand out because of deep rivalries or because the outcome will say something larger about the Democratic or Republican parties. Others matter because the winner could increase or decrease a party’s odds of winning in the general election.
Coming on to the list: Democratic gubernatorial primaries in Pennsylvania and Rhode Island as well as Nebraska's Republican Senate primary.
Coming off the list: Republican Senate primaries in Texas and Wyoming as well as the recently completed primary in Florida's 13th district.
To the Line!
Alaska's Republican Senate race: Former attorney general Dan Sullivan (R) arguably posted the most impressive fourth-quarter fundraising total, relative to his race, of any Senate candidate on the map. Sullivan turned heads after lapping Lt. Gov. Mead Treadwell (R) several times over in the money chase. Democrats have started to keep a closer eye on Sullivan as he begins to look more and more formidable. Also in this primary is disastrous 2010 nominee Joe Miller, who stands virtually no chance of winning, but could be a factor in a very close race. The winner will take on Sen. Mark Begich (D).
California's 31st district race: Rep. Gary Miller (R) announced his retirement this week, making a likely Democratic pickup a virtual lock. But the question is which Democrat will emerge victorious. (California's top-two, all-party primary system makes the question even more interesting.) There's Redlands Mayor Pete Aguilar, who is backed by the Democratic Congressional Campaign Committee; attorney Eloise Gomez Reyes, the choice of Emily's List; and a former congressman, Joe Baca. Baca seems like the longest shot of the three: He raised just $20,000 in the last quarter.
Georgia's Republican Senate race: Recent polling shows a wide open race, making this a must-watch contest ahead of the May 20 primary. Given that no candidate is running away, a runoff appears very likely. The conventional wisdom has long been that if Republicans nominate Rep. Paul Broun, it would be good news for Democrats, given Broun's tendency to make controversial comments. To his credit, Broun -- who nabbed the first national tea party endorsement in the race this week -- has run a pretty steady campaign so far, without any major blunders. But Democrats are still eager to see him face Michelle Nunn (D) in one of only two Senate races where the GOP is at risk of coughing up a seat it controls.
Hawaii's Democratic Senate race: The Aloha State is not expensive by campaign metrics, but money still matters -- and it's a good gauge of momentum. With that in mind, Sen. Brian Schatz (D) has the upper hand early over Rep. Colleen Hanabusa (D), who has struggled to keep pace in the fundraising chase. This is the latest chapter of a long-standing divide in state Democratic circles that falls along racial and generational lines.
Idaho's 2nd district Republican race: Last year ended on a high note for Rep. Mike Simpson (R): He outraised attorney Bryan Smith (R) more than 2-1 and got some backup from the Chamber of Commerce. Smith is backed by the anti-tax Club for Growth, a well-funded tea party group that isn't shy about spending money on candidates it likes. So don't count on a Simpson victory just yet. This contest is a key focal point in the business-vs.-tea-party battle in the GOP.
Kentucky's Republican Senate race: Matt Bevin (R) has about three months to close a major gap against Senate Minority Leader Mitch McConnell (R). So far, McConnell's in good shape. He's raising tons of money, and polls show he leads Bevin by a wide margin. A Politico story out this week about how Bevin once backed the TARP program he likes to slam made matters worse for the challenger. This is McConnell's race to lose right now. Still, when the top Republican in the Senate gets primaried, we pay attention until it's over.
Mississippi's Republican Senate race: As we wrote earlier this week, the pool of Senate Republican primary challengers is wider than it is deep. That said, if there's one race where things could get interesting, it's this one. State Sen. Chris McDaniel has impressed national tea party groups and shown that he can raise money. Meanwhile, it didn't help Sen. Than Cochran (R) that he clocked in as only the 34th most conservative member of the Senate, according to National Journal's 2013 vote ratings.
Nebraska's Republican Senate race: This race is unique in that it has split the tea party wing of the GOP. Midland University President Ben Sasse has the support of the Club for Growth and the Senate Conservatives Fund, while former treasurer Shane Osborn has the support of FreedomWorks. Regardless of who wins the GOP nomination, this race is a sure bet to stay in Republican hands.
Pennsylvania's Democratic gubernatorial race: We've heard a lot this cycle about Republicans being forced to move to the right. How about Democrats moving left? Rep. Allyson Schwartz (D) did just that last month when she cut ties with several centrist groups after coming under heat from liberals. Schwartz still looks like the front-runner here, but this race has become competitive in recent months. The contest includes well-funded former state revenue secretary Tom Wolf, former Ed Rendell administration official Katie McGinty, and Treasurer Rob McCord. To the victor go the spoils: A chance to take on deeply unpopular Gov. Tom Corbett (R) in the general election. Corbett is the most vulnerable governor running for a second term this cycle.
Rhode Island Democratic governor's race: As if a race featuring two blue chip rising Democratic stars wasn't enough, a third candidate recently jumped into the mix: Clay Pell, husband of former Olympic figure skating star Michelle Kwan and son of late Sen. Claiborne Pell (D-R.I.). Pell's connections may help him raise some cash, but the candidates to beat in this race remain Treasurer Gina Raimondo and Providence Mayor Angel Taveras. The winner of the primary will be a heavy favorite in the general election.