IRVINE, Calif.—While California continued trending bluer Tuesday, the state did not provide the seven solid pick-ups Democratic leaders had predicted despite the massive spending by outside groups and unprecedented Democratic registration and get-out-the-vote drives across the state.

As of early Wednesday morning, Democrats appeared to be holding on to victories in three out of seven highly targeted California congressional districts that voted for Hillary Clinton in 2016.

The mixed result came after Democratic and Republican outside groups spent more than $67.5 million in the general election in those battleground districts, more than doubling election independent expenditures for California's House races in the 2016 election.

For more than a year, Minority Leader Nancy Pelosi (D., Calif.) had claimed that the path to Democrats flipping the House would run through California.

In reality, Fox News, followed by the other major networks, began calling the House majority win for the Democrats early in the evening West-Coast time, before the first official votes in those races even began being counted in California.

Several hours later, California's mixed results began to take shape, with one more seat solidly in the blue column than Democrats had before election night and two more appearing to have flipped to the Democrats. Although with victory margins so slim, recounts in several of the races appear likely.

In the seat Rep. Darrell Issa (R., Calif.) left open by his retirement, environmental lawyer Mike Levin held a four-point lead over former state legislator and tax board member Diane Harkey, with 66 percent of the vote counted.

Republicans all but abandoned the contest in the general election as Democrats poured money into the race and Sen. Bernie Sanders (I., Vt.) waded in a week before voters went to the polls, touting Levin as a "progressive Democrat" who was dedicated to helping him pass his priorities—Medicare for all, free college tuition and a higher minimum wage—in Washington.

Levin, during his victory party at the Hilton Del Mar, argued that the district, which spans Southern Orange County and North County San Diego, "had rediscovered Democrats" after 17 years of Issa occupying the seat.

To the north in Orange County and north of Los Angeles, two Democrats were holding onto razor-thin leads.

Democrat Katie Hill appears to have edged out Rep. Steve Knight (R., Calif.) with a two-point lead 51 percent to 49 percent with 95 percent of the vote counted in the most expensive race in the state.

A week before election day, both sides had spent $15 million on the contest, with 25 outside groups deploying close to $10.4 million for Hill. Michael Bloomberg's group spent more than $5 million alone, while Knight's supporters, namely the GOP leadership-aligned Congressional Leadership Fund, devoted $4.6 million on his behalf.

Democrat Harley Rouda also appeared to have bested Rep. Dana Rohrabacher (R., Calif.), 51 percent to 49 percent in a once solidly red seat Rohrabacher has held for nearly three decades.

In the other highly competitive House races in the golden state, Republicans appeared headed to hard-fought victories. Rep. Mimi Walters (R., Calif.) was leading Democratic opponent Katie Porter by four points, 52 percent to 48 percent with all of the votes counted.

Before the night ended, she thanked her volunteers at her victory party at her Irvine headquarters and vowed to keep up the fight and engage in a continuous campaign to fend off a 2020 challenger early.

"Nancy Pelosi had to go after me in order to get the gavel back," she said Tuesday night, arguing the only way to win her traditionally conservative district was for Democrats to pour millions and millions of dollars into the fight "to try to take a seat they've never held before."

Republicans also appeared to hold onto the seat left open by retiring Rep. Ed Royce (R., Calif.) in a demographically diverse district that is home to the Richard Nixon presidential library. Young Kim, a former state legislator and aide to Royce for more than two decades, held a 51 to 49 percent lead over self-funder Gil Cisneros, a lottery winner and former Navy veteran.

In the Central Valley, Rep. David Valadao (R., Calif.) easily bested Democrat TJ Cox 54 to 46 percent and House Intelligence Committee Chairman Devin Nunez (R., Calif.) lead Democrat Andrew Janz by double digits, 56 to 44 percent despite being targeted by Democrats for his defense of President Trump in the Russia probe.

After months of intense jockeying, Rep. Jeff Denham (R., Calif.) also held a slim lead over Democrat Josh Harder, 51 to 49 percent with all of the votes counted.

And far to the South, indicted Rep. Duncan Hunter (R., Calif.) easily fended off Democrat Ammar Campa-Najjar. If Hunter resigns or is convicted on campaign-finance violations in the next two years, there will be a special election with Republicans poised to hold onto the seat in the heavily Republican district.