Liberal Supreme Court Justice Elena Kagan on Thursday expressed alarm at the increase in threats against the judiciary but said judges should not be intimidated, urging them to focus on their jobs as arbiters of the rule of law.

Speaking to an audience of judges and lawyers at a conference in Monterey, Calif., Kagan acknowledged that judges are frequent targets of harsh criticism, but said they should not be “aggravated or maddened” by it.

“The response to perceived lawlessness of any kind is law,” she added.

President Donald Trump and his allies have been particularly vocal in criticizing judges who have blocked his policies on a wide range of issues since he took office in January. Trump’s demand that a federal judge be impeached for ruling against the administration prompted a rare rebuke from Chief Justice John Roberts.

The judiciary has reported a spike in threats against judges and expressed concerns about whether they are sufficiently protected.

“Judges are fair game for all kinds of criticism, strong criticism, pointed criticism, but vilifying judges in that way is a step beyond and ought to be understood as such,” Kagan said.

“In the face of these sorts of threats to an independent judiciary, judges just need to do what they are obligated to do, which is to do law in the best way they know how to do, make independent, reasoned judgments based on precedent, based on other law, to not be inhibited by any of these threats,” she added.

Kagan also criticized how the Supreme Court, which has a 6-3 conservative majority, has increasingly issued important decisions in emergency cases without full briefing, argument or explanation. The Trump administration has often asked the court to intervene when its policies are blocked and the court has, in most cases, ruled in favor of the government.

“I think we should be cautious about acting on the emergency docket,” she said, with her biggest concern being the court’s failure to explain itself.

“I think more generally, it’s the courts that are supposed to explain things. That’s what courts do,” she added.