Those are words no Republican incumbent wants to hear. No one wants a challenger and a tea party challenger means that the incumbent 1) probably doesn't have a lot of grassroots support 2) he has a challenger that will be able to count on motivated volunteers that a normal challenger couldn't afford. Usually the tea party guys are underfunded and will struggle to pick up 40% of the primary vote.
Brian Bilbray is in the unfortunate situation of having: 1) Two Tea Party challengers 2) Both are using their own money in their campaigns 3) He's in a jungle primary.
Usually the more challengers a congressman has, the more likely he is to win. While a second challenger will siphon off some of his votes, he'll take more of the anti-congressman vote. On the other hand, if you don't like Brian Bilbray you have two alternatives, instead of one. These two challengers will not only be able to rely on grassroots support, the way tea party candidates can, but they'll also be able to spend money on advertising, consultants, and infrastructure.
The worst part of it is that it's a jungle primary, with Republicans, Democrats, and a couple "No Party Preference" candidates. While Democrats are unlikely to take any Bilbray voters, former Santee mayor Jack Doyle, an NPP, could. But what's worse is that the Democrats have the worst combination for the Republicans, 2 quality candidates. San Diego Port Chairman Scott Peters is popular and has raised good money, the things that make him a good candidate. Former assemblywoman Lori Saldaña hasn't raised as much money, but she has voters who've voted for her before and she's Hispanic. While this isn't a heavily Hispanic district, there are enough Hispanics that their votes could give Saldaña enough votes to beat Bilbray. Two good Democrats and three good Republicans is the perfect storm that could lead to Democrats ending up with two candidates in November.
Some might dismiss this idea. It's not like Bilbray is unpopular or underfunded. He's a good candidate who has been through tough campaigns before. But the tea party is unpredictable and the Democrats could easily split their vote just right to put them 1-2.
This is my #1 race for June 5. It's a competitive district that could go to either party, yet neither party's nominee is set. There are other exciting districts, but any district where whichever Democrat/Republican is a lock to win the seat has to be secondary.