LOS ANGELES >> Democrat Gil Cisneros captured a Republican-held U.S. House seat in Southern California today, capping a Democratic rout in which the party picked up six congressional seats in the state.

In what had been the last undecided House contest in California, Cisneros beat Republican Young Kim for the state’s 39th District seat. The Cisneros victory cements a stunning political realignment that will leave a vast stretch of the Los Angeles metropolitan area under Democratic control in the House.

With Kim’s defeat, four Republican-held House districts all or partly in Orange County, California, a one-time nationally known GOP stronghold southeast of Los Angeles, will have shifted in one election to the Democratic column. The change means that the county — Richard Nixon’s birthplace and site of his presidential library — will only have Democrats representing its residents in Washington next year.

Democrats also recently picked up the last Republican-held House seat anchored in Los Angeles County, when Democrat Katie Hill ousted Republican Rep. Steve Knight.

With other gains — Republicans also lost a seat in the agricultural Central Valley — Democrats will hold a 45-8 edge in California U.S. House seats next year.

The district was one of seven targeted by Democrats across California after Hillary Clinton carried them in the 2016 presidential election.

Cisneros, 47, a $266 million lottery jackpot winner, had been locked in a close race with Kim in a district that has grown increasingly diverse. It’s about equally divided between Republicans, Democrats and independents, as it is with Asians, Hispanics and whites.

Kim, 55, a former state legislator, worked for years for retiring Republican Rep. Ed Royce, who is vacating the seat and had endorsed her.

In a state where President Donald Trump is unpopular, Kim sought to create distance with the White House on trade and health care. Her immigrant background — and gender — made her stand out in a political party whose leaders in Washington are mostly older white men.

“I’m a different kind of candidate,” she had said.

It wasn’t enough. Democratic ads depicted her as a Trump underling, eager to carry out his agenda.

Cisneros, a first-time candidate, described his interest in Congress as an extension of his time in the military — he said it was about public service. He runs a charitable foundation with his wife.

On health care, he talked about his mother who went without insurance for 16 years. “That should just not happen in this country,” he had said.

While the election delivered mixed results around the U.S., it affirmed California’s reputation as a Democratic fortress.

Democrats are on track to hold every statewide office — again. The party holds a supermajority in both chambers of the Legislature — and a 3.7-million advantage in voter registration.

There wasn’t even a Republican on the ballot for U.S. Senate.