Here are some nominees:
The Democratic Congressional Campaign Committee, for lurching from candidate to candidate in some of these districts (until the end), giving voters little help in navigating ballots swimming with mostly unknown names.
The California Democratic Party, for failing to groom a bench of candidates for this moment — and for its largely unsuccessful efforts to clear the field.
California’s nonpartisan top–two election system. This election reform may end up producing the worst-case scenario Democratic and Republican leaders warned about when it was passed by voters in 2010. With so many candidates jumping into the open primary, Democrats are fighting over a set number of voters. From this point of view, there was little state or national Democrats could do.
The quirks that make the California primary risky for Democrats also make it a leading indicator of the general election.
In the state’s nonpartisan top-two system, voters can cast a ballot for any candidate, regardless of party. Historically, that means these top-two primaries look a lot like the general election.
Since 1990, the major party vote share in top-two congressional primaries in Washington State and California has differed from the general election result by an average of three percentage points, an Upshot analysis shows.
That means the California results will be about as good as any data we are going to get before November. The average House poll over the final three weeks of an election is off by an average margin of 6.2 points, according to FiveThirtyEight. The primary results are a bit like getting a free round of 52 final House polls in early June.
The results are good enough that you can put stock in a surprise. In 2016, Representative Darrell Issa’s seat was rated “Safely Republican” by the Cook Political Report heading into the primary. But he ended up with just 50.8 percent of the vote, the closest House election of the cycle.
If this is a wave environment like in 2006 or 2010, which would probably make the Democrats slight to modest favorites to retake the House, it should not be too hard to tell. (Read more here.)
The tsunami of emboldened Democrats running has some voters overwhelmed by choice.
Like many voters in Orange County, Tim Cain, 52, has been inundated with political messaging in recent weeks. He was bombarded with mail. His phone did not stop ringing.
“I literally could not go through my work day without getting flooded with calls,” said Mr. Cain, a video game developer. “I basically said, my phone is no longer available.”
But some combination of that barrage and his desire to support a Democrat drew him to a polling station at a Buick car dealership in Tustin on Tuesday morning in the 45th Congressional District.
About 20 miles south, at Laguna Beach City Hall, Aggie Dougherty had to thumb through the sample ballot packet she carried with her to remember which Democrat she had chosen after more than a dozen candidates inundated the 48th Congressional District with campaign material.
Ms. Dougherty, a 67-year-old bookkeeper, read the fliers that landed in her mailbox, talked to friends, and listened to the news and advertisements. Then, she selected Harley Rouda, the candidate endorsed by the Democratic Congressional Campaign Committee in an unusual move aimed at preventing Democrats from losing a spot on the November ballot by splitting the vote in the primary. This morning, she just needed to double-check.
“Oh, right,” she said. “Harley.”
Jenny Medina and Ivan Penn
‘We’re doing a personality test’: Some candidates express frustration with the top-two system.
In the 48th District, Scott Baugh, a Republican candidate and former Orange County party chairman, talked with voters about attack ads targeting him, including mailers and television advertisements.
“Those came from Nancy Pelosi, you know,” he said, referring to the ads. (The ads were paid for by the House Majority PAC, a heavily financed Democratic group.) “She is so afraid of me making the next round that she is trying to shut me out.”
Hans Keirstead, a Democrat running in the 48th, said he had “real fear that a party could be locked out this year.”
Rocky Chavez, a Republican candidate in the 49th District race who has had to face down the Democratic Congressional Campaign Committee in addition to his own party rival, also criticized the system. In a race that features 16 candidates, the campaign committee had attacked Mr. Chavez for fear that right-leaning Democrats might support him, further diluting the party’s chances.
“We’re doing a personality test,” said Mr. Chavez, who wore a Rocky Balboa T-shirt on Tuesday.
At least one Republican in the race enjoyed a bit of schadenfreude.
“These guys are going to split the race so wide,” said Ted Howze, a Republican candidate competing against five Democrats and the Republican incumbent in the 10th District. “The Democrats have shot themselves in the foot.”
But for Mark Kramer, 64, a retired maintenance worker in the hotly contested 39th District, none of the choices had appealed enough to induce him to cast a ballot. “Not crazy about the political climate,” he said at the post office on Birch Street in Brea, Calif. “Or any of the candidates.”
Jenny Medina, Jose A. Del Real, Thomas Fuller and Miriam Jordan
Facebook’s efforts to fight disinformation might have fallen short.
While Facebook announced new rules on April 6 mandating that campaign ads be clearly labeled and say who had bought them, the rules did not go into effect until late May, not long before the state’s primaries.
Facebook has said that the process it put in place is a “solid step,” but in a call with reporters last month, executives acknowledged that there would be instances where they did not catch ads that should have been labeled political campaign ads. (Read more in our story.)
That a family with different political views can agree gives Democrats hope for the 21st District.
On Monday afternoon, T.J. Cox, a Democratic candidate aiming to capture the Republican-held 21st District, visited with David and Dorothy Boldt, of D.E. Boldt Farms, at their ranch in the near-100-degree heat. Dorothy, a registered Republican, voted for Bernie Sanders for president in 2016, while her husband, David, a Democrat, said he held his nose and voted for Hillary Clinton. Both support Mr. Cox’s campaign.
“I care about the whole laundry list of progressive issues, from climate change to a more friendly and open attitude to immigration,” Mr. Boldt said.
Their son, Peter Boldt, 23, a registered Republican who also supports Mr. Cox, displayed an album of photos from their family’s farm, dating back five generations. As Mr. Cox sampled their plums, nectarines and peaches, David talked about how gentleness with the fruit is their specialty. Some of their produce is on shelves in Whole Foods; little stickers on the fruit have the farm’s name on them. “I get emails from Wall Street brokers saying ‘I bit into one of your plums!’” David said.
Mr. Cox peeled off a sticker and stuck it on his shirt like a campaign button.
On Tuesday, however, a group teenage interns were working the phones inside Representative David Valadao’s campaign office, where the Wi-Fi network includes the word “Victory.” They aren’t just targeting Republicans — they are also calling Democrats, and independents.
All the clamor about flipping the largely Democratic, rural district from red to blue is nothing to worry about, says Cole Rojewski, Mr. Valadao’s chief of staff.
“This district, the voters are really smart,” he said, mentioning issues like water storage and immigration. “They don’t vote on party, they vote on issues.”
At a polling location in Orange County, not everyone was looking for change.
In Lake Forest, Barry McLean, 74, a retired former Internal Revenue Service worker, said he had “no qualms” with Representative Mimi Walters, the Republican incumbent of the 45th Congressional District. “I tend to go with the political party I’ve always gone with,” he said.
Christopher Smith, 63, retired editor at The Orange County Register, said he voted for Katie Porter, a Democrat, because he believes she is the one who can beat Ms. Walters.
“If you’re a Democrat in Orange County, I think the primary election involves tactical choices,” Mr. Smith said.
One candidate has become something of a minor celebrity.
This year has broken records for the number of women running for office. Like many of them,, Katie Hill, a Democratic candidate in the 25th Congressional District, is a first-time candidate.
But with an endorsement from Emily’s List, and a relatively substantial war chest, Ms. Hill, 30, has emerged as a top contender in this traditionally Republican district where she grew up.
Vice News is filming a documentary about her campaign — a camera crew was present on Tuesday — making it feel a bit like the subject of a reality television show. When Ms. Hill, a nonprofit executive, arrived at a volunteer event, at the home of a supporter in the hills of Simi Valley, someone posed with her for a selfie.
In a brief interview, she said she felt “really good about today.” Up next on her agenda was writing her primary night speech. Was she writing two drafts, one for either possible outcome?
“I’m probably going to write one version,” she said “with a twist.”
[Take a look at how female candidates in notable races could fare on Tuesday.]
Another candidate would give the president a book on climate change.
Sit down with Mike Levin, a Democratic candidate in the 49th Congressional District, and the conversation will quickly turn to climate change. Mr. Levin, an environmental lawyer, chose to run for the seat, he said, in part because he heard so few politicians talking about the environment in 2016.
Last year, Mr. Levin drew attention over his appearance at a town hall event for the incumbent, Mr. Issa, in Oceanside, Calif., in which he described giving Mr. Issa a book on climate change.
“Why do you blindly support Donald Trump’s agenda to gut the E.P.A., to gut basic science?” he asked Mr. Issa at the time, as activists cheered him on. The dynamics of the race changed after Mr. Issa announced he would not seek re-election; now Mr. Levin, facing other Democrats, hopes to consolidate support to make it onto the general election ballot.
When asked what he would say to Mr. Trump if they were in a room together, Mr. Levin said he would give the president the same climate change book he gave Mr. Issa. “Mr. President, this issue is too important. Listen to Ivanka,” he imagined saying, invoking Mr. Trump’s oldest daughter, who urged her father to keep the United States in the Paris climate accord.