Democracy and the rule of law are under threat in the United States. So it was heartening to see thousands of Americans gather around the country at short notice to protest Trump and the Republican party’s authoritarian tendencies, rallying to demand protection for Robert Mueller’s nearly-finished investigation into possible collusion between the Trump campaign and the Kremlin.

The mobilization effort was impressive. Overnight, a coalition of some of the country’s most progressive groups, including MoveOn.org, Common Cause, Public Citizen, and Indivisible, organized nationwide protests (and even some in Canada) against Trump’s firing of “white nationalist” (read: white supremacist) attorney general Jeff Sessions and the ascension of the anti-Mueller-probe Matthew Whitaker to the post. Ordinary people, many of them likely newly politicized in the Trump era, braved cold weather on a weeknight to take a stand for democratic ideals.

“It’s happening,” said MSNBC host Rachel Maddow, calling the situation an “emergency.” “We knew this would happen at some point — the day has arrived.”