This November, California Senator Dianne Feinstein will be running for a fifth full term in the upper chamber, capping off a career on the public payroll dating back to her time as Municipal Supervisor of San Francisco back in 1970. She’ll be facing fellow Democrat Kevin de León, who she bested by a wide margin in the state’s primary earlier this year. But in a stinging rebuke from her own party, California Democrats this weekend determined that she would be running without their endorsement, preferring to instead back her opponent. Feinstein clearly saw this coming and had been negotiating in the background all week to encourage the party to endorse neither of them rather than snubbing her, but those efforts fell short yesterday. (NY Times)

Six weeks after winning an overwhelming victory among California primary voters, Senator Dianne Feinstein suffered an embarrassing setback Saturday night as the state Democratic Party officially endorsed her rival for election this November.

Kevin de León, the Democratic leader in California’s State Senate, won the support of the party leadership despite an effort by Ms. Feinstein to convince the party not to offer an endorsement.

The vote for Mr. de León reflected the rise of younger liberal activists in the California Democratic leadership, some of whom regard Ms. Feinstein as a moderate compared with the intensely progressive voices who are coming up through the party ranks. These activists tend to be younger and more left-leaning than the state party at large.

The state senator was, of course, thrilled with the result and took to Twitter to celebrate.

This development will rightly be viewed as yet another instance of the growing schism inside the Democratic Party, where the “new breed” of far left, socialist supporters and candidates are increasingly rejecting their older, more “mainstream” leadership in favor of various flavors of Berniecrats. The funny part of this is that de León isn’t particularly young or “radical” in that sense, though he’s certainly been speaking the language of the far left throughout the primary. His actual name is Kevin Alexander Leon (he’s never legally changed it to the more ethnic sounding version he’s been using for decades) and at age 51 he’s been knocking around state politics and labor unions for decades. Still, I suppose he comes off looking more young and radical when compared to Feinstein.

This is likely to wind up being little more than a case of poor optics for the incumbent and she’s facing this embarrassing outcome strictly as a result of the state’s “top two” primary system. Feinstein is still likely to win easily, but the margin will be much, much less than if she were running against a Republican. The irony is that the top two primary is once again exacerbating internal party struggles rather than just shutting out Republicans as Democrats originally intended. If Feinstein were facing the top finishing GOP candidate there would have been zero question of her receiving the endorsement and getting nearly all the available Democratic votes in the state. But now she’ll have to deal with de Leon siphoning off much of the youth vote as well as (most likely) a bunch of GOP voters who just want to see her take a black eye in November.

Exit question: Will Alexandria Ocasio-Cortez be coming out to the west coast to campaign for de Leon? After all, she’s already expected to save the world.