LOS ANGELES, United States (AFP) — California is spearheading a new resistance to the incoming Donald Trump administration that will test the power of Democratic states to battle mass deportation, defend reproductive rights and combat climate change.

Trump’s sweeping election victory this week came off the back of promises to swiftly expel millions of illegal immigrants and roll back nationwide environmental protections. Critics fear his allies could move to restrict access to abortion medication.

But under the US constitution, states wield significant power and any such moves will certainly be met with lawsuits.

California’s top prosecutor stood in front of San Francisco’s Golden Gate Bridge this week and vowed to “take on the challenges of a second Trump Administration — together.”

“We lived through Trump 1.0. We know what he’s capable of,” California Attorney General Rob Bonta said.

“We’ll continue to be a check on overreach and push back on abuse of power,” he promised.

Governors and attorneys general of other liberal states including New York, Illinois, Oregon and Washington have made similar proclamations.

“If you try to harm New Yorkers or roll back their rights, I will fight you every step of the way,” Governor Kathy Hochul vowed.

“You come for my people, you come through me,” Illinois Governor J.B. Pritzker said, as Democratic prosecutors across the nation coordinate their strategies.

The pre-emptive maneuvers have swiftly drawn the ire of Trump, who singled out California Governor Gavin Newsom in an angry social media riposte Friday.