Republicans target Trump voters in California push

The GOP's congressional campaign arm has mounted a six-figure digital effort focused on turning out Donald Trump voters in several of next week's California primaries, engaging in an early test of how to juice political participation from the president's base in some of the most potentially challenging districts for Republicans in the country.

The National Republican Congressional Committee's efforts are playing out in the primaries in Southern California's 39th, 48th and 49th Congressional Districts — each of which Hillary Clinton won in 2016. Those districts are also causing Democrats heartburn at the moment as they scramble to survive their own crowded primary fields to land a spot on the ballot in California's nonpartisan, top-two primary system. The top two vote-getters in next Tuesday's races, regardless of party, will advance to match-ups in November, and Democrats openly acknowledge they are worried they might become locked out of the general election in some of them.

But the NRCC still sees an opportunity to experiment with longer-term turnout strategy in those districts, which Democrats have long seen as top pick-up opportunities in the fall campaigns.

To that end, the NRCC is deploying ads on Facebook, Google and Pandora, and has plans to run a text message program closer to Election Day. They are also launching ads aimed at Korean- and Mandarin-speaking Republicans, potentially significant constituencies in California's diverse districts.

The ad campaign pushes for Election Day voting or the return of vote-by-mail ballots. The initiative, which began on May 25 but hasn't been previously reported, will go through primary day next Tuesday.

Katie Glueck: 202-383-6078, @katieglueck