Voters struck down the effort to recall Gov. Gavin Newsom, continuing the political seesawing that has defined the former Republican stronghold.LADERA RANCH, Calif. — When Gail Grigaux first moved to Ladera Ranch in Orange County from the East Coast more than 15 years ago, she knew she had arrived in the conservative heart of Southern California.“If I met anybody new, I would assume they were Republican,” said Ms. Grigaux, 53, a teacher’s assistant.It often felt that way, even as recently as last year when supporters of former President Donald J. Trump drove golf carts with Trump flags and sold Trump paraphernalia on street corners of the master-planned suburban community. But the Democratic side has been nearly as visible lately. A Ladera Ranch social justice Facebook group formed.“I got my little Black Lives Matter sign,” Ms. Grigaux said. Ladera Ranch, much like Orange County itself, is changing.In 2018, Democrats flipped four House seats in Orange County, turning the county entirely Democratic for the first time in the modern era. But in 2020, Democrats ceded two of those seats back to the Republicans even as Mr. Trump lost both Orange County and California overall.Now, in 2021, Democrats have swung Orange County back once again, helping Gov. Gavin Newsom stop the Republican attempt to recall him. Fifty-two percent of voters in Orange County, including Ms. Grigaux, opposed the recall, compared to 48 percent in favor, though the results are still not official.The county’s seesawing status has consequences far beyond its 3.2 million residents, as strategists of both parties see it as a bellwether of key suburban and diversifying House districts nationwide in the 2022 midterms.Many of the touchstones of Orange County’s storied conservatism — the birthplace (and resting place) of Richard M. Nixon, the incubator of the right-wing John Birch Society, the political base of Ronald Reagan — are now decades out of date. The county has steadily transformed into one of the nation’s premier electoral battlegrounds, a place where political and demographic cross currents are all colliding.Nestled along the scenic coastline south of Los Angeles, Orange County has seen an influx of Asian and Latino residents and a backlash from some white voters resistant to change. The college-educated and affluent white voters who once were the backbone of Orange County Republicanism have increasingly turned away from the G.O.P. in the Trump era.The old Orange County represented the cutting edge of Republican politics. Now, in many ways, the county represents the new face of America, and its divisions.“Orange County used to be reliably Republican when it was fairly homogeneous,” said Jim Brulte, a former chairman of the California Republican Party who lives in San Juan Capistrano. “We’re not that Orange County and we haven’t been that Orange County for two decades.”Today, more than one in three of the county’s residents are Hispanic and more than one in five are Asian, according to census data. Forty-five percent of residents speak a language other than English at home. In Santa Ana, 96 percent of the 45,000 students in the school district are Latino. Not far away is Little Saigon, home to the densest population of Vietnamese Americans in the nation. The two Republicans who won back House seats in 2020, Michelle Steel and Young Kim, are both Asian American women.“In Orange County, if you run a cookie-cutter campaign, you are going to lose,” Mr. Brulte said.In Mr. Newsom’s resounding statewide recall victory, and his narrower advantage in Orange County, Democrats see something of a road map for the midterms. Mr. Newsom had carried Orange County by a narrow 50.1 percent in 2018, the year that Democrats picked up four House seats. He outpaced that margin in the recall, winning 52 percent. Roughly 90 percent of the vote had been counted as of Friday evening, with an estimated 130,000 ballots still to be tallied.A senior adviser to Mr. Newsom, Sean Clegg, said the campaign’s analysis of the remaining ballots suggested the governor’s lead would swell further in the coming weeks. He offered a theory for the governor’s success. “Orange County is national ground zero for the realignment of college-educated voters away from Trump’s Republican Party,” Mr. Clegg said, adding that vaccines had proved a particularly potent issue.Ladera Ranch in Orange County is wealthier than California as a whole, with a median household income of $161,348.Allison Zaucha for The New York TimesFifty miles south of Los Angeles, Ladera Ranch is an unincorporated maze of well-kept townhomes and tract mansions first built in the rolling foothills of southern Orange County about two decades ago. Its population of 26,170 is whiter and richer than California as a whole: The median household income, $161,348, is a little more than double the state median.As in other wealthy bedroom communities stretching between Santa Ana and San Diego, many residents are outspoken conservatives who in recent years became ardent supporters of Mr. Trump. Earlier this year, federal investigators raided the Ladera Ranch homes of two men in connection with the Jan. 6 siege on the Capitol.Other Trump voters in Ladera Ranch supported the former president more reluctantly.Andrea Dykstra, 40, a stay-at-home mother who has lived in the community for a decade and who identified as “more a libertarian than anything else,” said Mr. Trump was the best choice of less-than-ideal options.“Things are getting so polarized, it’s almost impossible to find more moderate voices,” she said.Ms. Dykstra was, however, passionate about recalling Mr. Newsom, whom she called corrupt and overreaching in his coronavirus pandemic restrictions.“I felt much more strongly that Newsom as governor has a lot more power over my day-to-day than the president does,” she said.Wendy Mage, 57, remembered that when she first lived in Ladera Ranch more than a decade ago, her neighbors vocally opposed gay marriage during California’s epic battle over Proposition 8, a measure to ban same-sex marriage.She moved away and returned with her husband in June to be closer to her mother. This time, she was pleasantly surprised to see a rainbow flag flying.“Oh,” she recalled thinking. “Ladera’s coming around.”Even the smallest shifts in Orange County are tracked closely in Washington. Representative Sean Patrick Maloney, a Democrat of New York and the chairman of the Democratic Congressional Campaign Committee, said he was feeling bullish after studying the recall results in Orange County — not just for particular seats up for grabs in 2022 but because he sees the region as an indicator of what’s to come.“What I think is important about Orange County is that it’s a good approximation for a battleground district,” Mr. Maloney said. “And it’s a good barometer for where things stand.”For now, the recall is clinging to a roughly 9,500-vote lead in the district of Ms. Steel, the Republican whose seat is contained fully in Orange County. In another Orange County congressional seat, held by Representative Katie Porter, a Democrat, the Republican recall effort was trailing by more than 18,000 votes.Ms. Porter downplayed any comparison between Mr. Newsom’s campaign and her own next year. While Mr. Newsom’s anti-recall rhetoric worked statewide, she said, “that is not a strategy that allows you to productively engage Republicans.”In contrast, Ms. Porter said her emphasis on oversight and accountability work has resonated with constituents regardless of party, even as she has carved out a national reputation as an outspoken progressive.Looking ahead to next year, she said it would be tough to guess “how you would best engage across party lines,” without knowing more about the direction of the Republican Party in Orange County and beyond.Voters cast their recall ballots in Anaheim in Orange County, which has steadily transformed into an electoral battleground. Allison Zaucha for The New York TimesMr. Trump made his biggest gains in Orange County in 2020 around Little Saigon and in Santa Ana, compared to his 2016 results, making inroads in the Vietnamese American community and among working-class Latinos as he hammered Democrats as socialists.But a preliminary 2021 results map from Vance Ulrich, of the nonpartisan consulting firm Redistricting Partners, shows Mr. Newsom’s anti-recall campaign succeeding in places like Garden Grove, Westminster and Santa Ana, cities where Mr. Trump had improved his performance in 2020. Majority-Vietnamese precincts swung heavily from their support of Mr. Trump in 2020 to opposing the recall, Mr. Ulrich said.At the same time, Irvine, one of the largest cities in the country where Asians are the dominant group, has become more solidly blue territory.Marc Marino, 26, has lived in Irvine for most of his life, moving with his parents, who are of Filipino descent, from Hong Kong when he was small. He said his first introduction to politics was through his family’s church, where he remembered leaders advocating Proposition 8, the measure to ban same-sex marriage.Mr. Marino said he eventually stopped going to church, and now identifies as “more of a Berniecrat.” Many of his friends from home have also parted political ways with their more conservative immigrant parents.“Most of my friends have shifted more left,” he said, “which I didn’t expect.”On Tuesday, he cast a ballot against the recall. As a health care worker, he supported Mr. Newsom’s pandemic response.Focusing on the pandemic, the Newsom campaign relentlessly pounded Larry Elder, the Republican front-runner, as a Trump-style candidate who wouldn’t prioritize containing the virus.The result statewide was that 64 percent of vaccinated independent voters opposed the recall, according to David Binder, Mr. Newsom’s pollster. The small slice of unvaccinated independents went overwhelmingly in favor of the recall.“Vaccinations are the driving issue polarizing our electorate in a way that is stronger than standard demographics,” Mr. Binder said.Neal Kelley, who has served as the Orange County voter registrar for the last 16 years, began his job when Republicans still dominated the county rolls. Now there are roughly 10 percent more registered Democrats than Republicans.Mr. Kelley is already hearing word of national efforts by both parties to boost their voter registration ahead of 2022. For now, Democrats keep pressing their advantage.Between the 2020 election and the recall, Republicans added 654 voters to their party rolls, according to state records.In that same time, the Democrats added 22,564. More