Rep. Young Kim will face fellow Republican Ken Calvert in bid for Southern California US House seat

The seat represents an area southeast of Los Angeles.

THIS IS A BREAKING NEWS UPDATE. AP’s earlier story follows below.

Republican-turned-Independent Rep. Kevin Kiley and former Democratic state Sen. Richard Pan both advanced to the November election on Tuesday, setting up a significant test of whether Democrats' redraw of California's House of Representatives' maps will pay off for the party.

For a few days after last week's primary, the suburban Sacramento district was a possible warning sign for Democrats, as Kiley and a long-shot Republican who ran on peace in the Mideast held the top two slots in the nonpartisan primary. But the state's slow but regular tally of late Democratic-mail ballots catapulted Pan onto the November ballot.

Democrats broke up Kiley's conservative Northern California district, so the congressman opted to run in the new, Democratic-leaning 6th Congressional District, left the GOP and became a vocal opponent of partisan redistricting.

California Democrats scrambled their map to counter gains Republicans made in Texas and elsewhere after President Donald Trump called for the GOP to create as many conservative seats as possible in its bid to hold onto the House of Representatives in November.

California’s 52 House races provided a miniature of national trends. That included the fallout from redistricting ahead of this year’s midterm elections, this time with Democrats redrawing the map, the generational battle among Democrats and questions of whether moderates or liberals are better positioned to win in swing districts.

Also on Tuesday in the state's capitol region, a major generational Democratic clash was set up as Sacramento City Councilwoman Mai Vang advanced to face longtime incumbent Rep. Doris Matsui on the November ballot.

The 81-year-old congresswoman has held the Sacramento-based seat since the death of her husband, former Rep. Bob Matsui, in 2005. Bob Matsui had represented the district since the 1970s.

Vang, 41, is one of a slew of Democrats across the nation mounting an explicitly generational challenge in the wake of Joe Biden’s presidency.

“People are tired of leaders who answer to their biggest donors instead of the families they represent,” Vang said in a statement after the race was called. “The squeeze on working families doesn’t check your party registration — and neither will I.”

Matsui released her first ad of the general election Tuesday night, focusing on a local mother whose son had muscular dystrophy and who praised Matsui for legislation funding therapies for the disease.

Two other veteran House Democrats in California also made it past younger challengers to the November ballot. Rep. Brad Sherman, 72, a 15-term congressman representing part of Los Angeles, will face a Republican in the fall. Mike Thompson, 75, is seeking his 13th term in a Northern California district.

In San Francisco, a wealthy progressive challenger was unable to crack the top two slots to fill retiring Rep. Nancy Pelosi’s seat. Instead, state Sen. Scott Wiener and city Supervisor Connie Chan will face off to replace the former House speaker.

The 7th District seat held by Matsui is considered a safe one for Democrats, but was redrawn as part of the party’s bid to add five more U.S. House seats elsewhere. Voters signed off on the changes with a constitutional amendment last year.

Democrats initially were concerned about getting locked out of the general election in a San Diego-area seat under the state’s primary system, which sends the top two vote-getters to the November ballot regardless of party. But San Diego City Councilwoman Marni von Wilpert managed to emerge from a large field of other Democrats and will face Republican Jim Desmond, a San Diego County supervisor.

The party got a scare in a redrawn district near Sacramento when an independent and a long-shot Republican candidate shared the top two slots after the initial ballot count. Later results showed one of the Democratic candidates, former state lawmaker Dr. Richard Pan, leaping into the top two.

In Southern California, Democrats drew two prominent Republican members of the House into the same district, triggering a monthslong primary battle between Rep. Ken Calvert and Rep. Young Kim over who has been more loyal to Trump. Calvert, who represented a larger share of the district before the remap, won one of the two top slots.

And in the Central Valley, Republican Rep. David Valadao, widely considered one of the most vulnerable House Republicans, is waiting to see if he will face centrist Democrat and Assemblywoman Jasmeet Bains or progressive political science professor and school board member Randy Villegas in November.