What happened?

It’s all about context, said Jack Citrin, a political science professor who leads Berkeley’s Institute of Governmental Studies, which conducted the polls.

“Partisanship was much less a factor” in 2015, he said. “But now I would say in California, whenever you ask pretty much any political question that may have some connection to Trump, you get a huge, huge partisan divide.”

President Trump’s vow to step up deportations has been deeply unpopular on the predominantly blue West Coast. As a result, the Democrat-controlled State Senate this month passed a measure that would essentially turn California into a “sanctuary state.”

Kevin de León, the leader of the State Senate and sponsor of the bill, said it was “a rejection of President Trump’s false and cynical portrayal of undocumented residents as a lawless community.”

But Republicans and some law enforcement leaders have argued that the Democrats are getting carried away with their antipathy toward the president.