Senator Barbara Boxer (D-CA) has announced that she will not run for reelection.
In the Democratic race, Lieutenant Governor Gavin Newsom and Attorney General Kamala Harris have the advantage of statewide name recognition. They may end up with a tacit understanding that one will run for Senate in 2016 and the other will run for governor in 2018, but the hard part will be deciding who runs for which office. Some Democratic House members may be also be looking at the race. It seems likely that the GOP will hold the majority in the House for a few more years at least, whereas Democrats have a reasonably good chance of regaining the Senate next year. (Ed Markey of Massachusetts, who was among the most senior House Democrats, gladly ran for the chance to be the least senior member of the Senate Democratic majority.)
It would be really hard for a Republican to win a Senate seat in California. No Republican has done so since Pete Wilson in 1988. Republicans can sometimes win blue-state governorships (Illinois, Maryland, and Massachusetts in 2014, for instance), but a senatorial election is a different kind of vote. National issues and party identification play a bigger role in Senate elections: only 15 senators come from statesthat went for the opposite party in the 2012 presidential election. In California, party registration and party identification are deep blue. And since 2016 will be a presidential election year, we can expect Democratic turnout to be reasonably high in California.
Republicans have a weak bench in California. They hold no statewide offices. No Republican House member from California has statewide name recognition. Even House majority leader Kevin McCarthy is a familiar name only among political junkies. If Californians have heard the name at all, they’ll think of the actor who starred in Invasion of the Body Snatchers.
There are a couple of significant GOP mayors, Kevin Faulconer of San Diego and Ashley Swearengin of Fresno, but they are little-known statewide. (Swearengin ran for controller in 2014, and lost.)
Running in California requires lots of money. Rep.Darrell Issa is very wealthy, and may wish to move up now that term limits have forced him to give up the chair of the House Oversight Committee. But he is probably too conservative to win statewide, and ethics issues would dog him in a statewide campaign. There may be other rich Republicans out there, but memories of Meg Whitman may deter them. In the 2010 gubernatorial race, she spent lavishly from her eBay fortune, but still lost badly to Jerry Brown.
With some financial backing, a moderate-to-liberal Republican might have an outside chance. Schwarzenegger designed the top-two primary to encourage the nomination of such candidates, but evidence for its effectiveness is mixed. Anyway, it is hard to identify who the moderate-to-liberal Republican would be. Tom Campbell ran against Feinstein in 2000 and lost by nearly 20 points. Neel Kashkari had to spend a large share of his personal funds to run for governor in 2014, and it is unlikely that he could afford to run statewide so soon.