Democratic California Senator Dianne Feinstein won her primary race, though it remains unclear who she will face in November's general election.
"They know who we are, and they don't like us", former state Republican Party Chairman Duf Sundheim lamented in 2010, after Democrats made a clean sweep of eight statewide contests.
While California has drawn the most attention, the Golden State was not the only one going to the polls on Tuesday.
Given the state's unique election laws it will take days to sort out its competitive races and determine winners. Because of its primary system, in which the top two vote-getters advance to the general election regardless of party, Democratic operatives were concerned that the party could get shut out in places it needs to compete in this fall. That allows the possibility of two candidates qualifying from the same party - and neither from the other.
No state offers Democrats more opportunities to gain House seats this fall than California, where more than a half dozen Republican-held seats may be in play. "If we are to take back the House, we have to win multiple districts in California".
Feinstein won her party's nomination for another term, as widely expected.
A Republican-backed effort to repeal the tax increase is likely to be on the November ballot, and the Newman recall election is an early test of where voters stand.
Much of the day's drama focused on women, who fought to make history in some cases and to avoid disaster in others. She will face former Democratic Rep. Bobby Bright in Alabama's conservative 2nd district - where Trump loyalty has been a central issue.
If there was any doubt that the Republican Party was now the party of Donald Trump, Tuesday's results in a deep-red Alabama congressional race should put it to rest.
On the whole, Tuesday was a successful night for women candidates, 122 of whom appeared on ballots across the country - the most on any single primary day in USA history. If Grisham wins, she'll be the second Latina to become the state's executive, after Martinez. In South Dakota, Congresswoman Kristi Noem won the Republican gubernatorial primary, making her likely to become South Dakota's first female governor. The incumbent lawmaker outran Mr. Trump in the district by 16 percentage points, according to the Los Angeles Times, and is favored by political handicappers in his general election race against Democrat T.J. Deciding is hard (as we saw during the 2016 Republican presidential nomination contest) in expanded, networked parties because there's nothing even remotely like a formal hierarchy.
"And so the people that went to the polls yesterday, they did so, because they have a sense that things are out of control", Patterson said.
There are now seven Republican lawmakers - from Rep. Jeff Denham in the northern San Joaquin Valley to Rep. Dana Rohrabacher in Southern California - who occupy House seats in districts that Hillary Clinton won in 2016. Cox also had been doing well in preliminary polling and received a significant bump after receiving an endorsement from President Trump in the middle of May.
In New Jersey, Republican Steve Lonegan, who was critical of Trump in 2016, lost a congressional primary after his opponent used footage of Trump criticizing the candidate in his ads. "A lot of us felt it was necessary to take a seat at the table".
Republicans now control both the House and the Senate. However, it should be remembered that in some of these districts, especially the 10th and 48th congressional districts, the second-place Democratic candidate is only narrowly ahead of a third-place Republican. He and Cox emerged from a field of six major candidates fighting it out in an expensive and contentious race to succeed Brown, setting up a pitched battle for the future direction of the nation's most populous state.