California has some of the toughest gun laws in the nation, including a ban on the type of high-capacity ammunition magazines used in some of the nation’s deadliest mass shootings.

How long those types of laws will stand is a growing concern among gun control advocates in California and elsewhere.

A federal judiciary that is becoming increasingly conservative under President Donald Trump and the Republican-controlled U.S. Senate has gun control advocates on edge. They worry that federal courts, especially if Trump wins a second term next year and Republicans hold the Senate, will take such an expansive view of Second Amendment rights that they might overturn strict gun control laws enacted in Democratic-leaning states.

The U.S. Supreme Court so far has left plenty of room for states to enact their own gun legislation, said Adam Winkler, a gun policy expert at the University of California, Los Angeles School of Law. But he said the success of the Trump administration in appointing federal judges, including to the high court, could alter that.

“Those judges are likely to be hostile to gun-control measures,” Winkler said. “So I think the courts overall have made a shift to the right on guns. We’ll just have to see how that plays out.”

The legal tug-of-war already is playing out in California.

The state banned the sale of high-capacity ammunition magazines nearly two decades ago as one of its numerous responses to deadly mass shootings; a voter initiative passed three years ago expanded on that, banning all ammunition magazines holding more than 10 rounds even among gun owners who already possessed them.

Earlier this year, a Republican-appointed federal judge overturned the ban, triggering a weeklong bullet buying spree among California gun owners before he put his decision on hold pending appeal. The same judge is overseeing another lawsuit brought by gun-rights groups that seeks to repeal a state law requiring background checks for ammunition buyers.

Legal experts, lawmakers and advocates on both sides said the decision in the case over ammunition limits foreshadows more conflicts between Democratic-leaning states seeking to impose tighter gun laws and an increasingly conservative federal judiciary.