The above pic is from Tigard, OR. A crowd this size in a small town is quite significant. Big city crowds could be in the 6 figure range.
So, looks like a solid turnout nationwide, which is a good beginning for a mass movement. With good weather coming, it would be a good time to organize a big March on Washington and/or an Occupy movement and take over all the National Parks or the buildings of the agencies he's closed.
Of course with Trump's psychology, this just means he will double down on everything and call the actions illegal and label the protesters terrorists. He'll probably incite his MAGA thugs as agents provocateur to turn the actions violent, then declare Martial Law.
I expect things to get worse before they get better. If they ever do.
'Hands Off!' protesters across US to rally against President Donald Trump and Elon Musk
https://www.cnn.com/2025/04/05/us/hands-off-protests-trump-musk/index.html