For a second night on Wednesday, thousands of protesters gathered in cities across the state to denounce the idea of a Donald J. Trump-led America, with some chanting, ”Not my president!”
On social media, the hashtag #Calexit took off, echoing the British decision to leave the European Union.
And in Sacramento, a joint statement from legislative leaders said, “Today, we woke up feeling like strangers in a foreign land.”
For one group, the postelection reaction has been electrifying. Yes California, a grass-roots organization with 3,000 or so supporters, has for years been trying to persuade Californians to take up the cause of secession.
“We hit it big with Trump being elected,” Marcus Ruiz Evans, a spokesman, said on Wednesday.
But Mr. Evans may be on to something. After Mr. Trump clinched his victory late Tuesday, at least three tech investors signaled a willingness to finance a secession effort.
Shervin Pishevar, a co-founder of Hyperloop One, announced on Twitter that he would back a “legitimate campaign” for California to become its own nation.
Marc Hemeon, another entrepreneur, responded to Mr. Pishevar saying to count him in. So did Dave Morin, a founder of the social network Path.