It's not easy being a Republican in California, where the Grand Old Party could soon join the Yosemite toad and Mohave ground squirrel on the list of threatened species. It's harder still being a Republican in left-leaning strongholds such as Sacramento and the San Francisco Bay Area.

But it's hardest of all living in those blue bulwarks and supporting President Donald Trump.

Living behind the Blue Curtain requires certain survival skills, backers of the president say. No bumper stickers, lest someone key your car. No signs, in the window or planted on your front lawn, to prevent vandalism. Steer clear of Facebook and other online forums, and don't discuss politics in the real world if you can help it.

"You kind of keep your head down," said Danny Turner, 29, a Trump supporter in the East Bay suburbs of San Francisco who waits tables as he prepares to launch a stock-picking newsletter. "You can't be very loud about it."

He learned that when someone in Turner's Livermore neighborhood put up a Trump lawn sign last fall and had their car and home plastered with blue spray paint. The word "fascist" — misspelled, Turner said — was left as a calling card on the sidewalk out front.

Trump received just under 600,000 votes in the nine-county San Francisco Bay Area and nearly 200,000 more in nearby Sacramento County. That's more than his totals in 21 states and the District of Columbia.

Still, he was swamped by Democrat Hillary Clinton, who carried California in the biggest landslide since Franklin D. Roosevelt in 1936. Here in San Francisco, Trump won a blink-and-you-missed-it 9 percent of the vote. Across the bay, where Turner lives in Alameda County, he mustered just 15 percent support.

In those liberal bastions of California, supporters of the president stand out like red pinpoints on a vast blue canvas — if, that is, they're willing to reveal themselves publicly.

"Someone gave me a Donald Trump T-shirt with Tupac on it," Turner said, referring to an improbable pairing of the president with the late rapper, Tupac Shakur, who attended high school in the Bay Area and claimed Oakland as his home. "It's pretty funny."

He has yet to wear it outside, however.

Living as a political pariah has dampened what might otherwise be a time of celebration — the end, as some Trump supporters see it, of a dark eight-year period in the country's history.

Dee Dee, 66, a part-time substitute teacher in Contra Costa County, where Trump scratched out 25 percent of the vote, said for years she put up with grating talk about the virtues of President Barack Obama and, more recently, Democratic presidential nominee Clinton. (She asked that her last name not be published, to avoid harassment.)

When Trump won, she said, the lunch-room conversation turned to shock and horror, and pretty soon that grew tiresome as well. "I finally said, 'Excuse me, I'd like to have a safe zone where I can come and eat peacefully and not listen to all this moaning and groaning.'"

Gloating, of course, would be out of the question. "You don't bring up the subject," she said.

Clinton's landslide margins in California are part of a broader social and political trend, as Americans continue to sort themselves into like-minded enclaves.

Across the country, more than 6 in 10 voters cast ballots in counties that backed Clinton or Trump with at least 60 percent support. About half the voters lived in such landslide counties in 2012, compared with fewer than 40 percent in 1992.

Of the nation's 3,113 counties or their equivalent, less than 1 in 10 — just 303 — were decided by single digits, said David Wasserman, an elections analyst with the nonpartisan Cook Political Report.

Even in bluest California, where they make up a distinct minority, not every Trump supporter feels oppressed or intimidated.

Katy Grimes, 54, a reporter and Sacramento columnist for the Flash Report, a conservative blog, proudly wears a pink camo baseball cap and a tank top emblazoned with "Make America Great Again" on runs through her Land Park neighborhood.

"I don't make it a secret at all," she said of her fervent Trump support, though she has a hard time understanding the hostility that abounds in the leafy, upscale community near the Capitol. "People here — neighbors, friends — they're just seething." (Trump won 34 percent of the vote in Sacramento County.)

She's heard some gasps and endured some hisses as she sports her pro-Trump regalia, Grimes said, but no one has tried to mess with her. "I do have a big German shepherd," she said.

As for Ring, the Sacramento policy analyst, he managed to salvage at least one long-standing relationship.

For a time, he said, he feared his pro-Trump stance had gotten him banned from the home of another close friend, who'd been the best man at his wedding. "I was pretty upset," Ring said, but after he posted a lament on Facebook his chum's wife called to say it was all just a misunderstanding and he was welcome to visit.

Still, he's proceeding with caution.

"We probably won't talk about politics," Ring said, "and if we do it will be because she wants to. I will not bring the subject up."