Just so there's no confusion, Trump didn't do that himself. When it comes to the safety of the President the SS has the final say. Trump has to listen to what they want him to do.
Listen, sure, but I doubt he must follow their directions.
They probably would've denied him that stroll earlier if they had absolute say in the matter.
Probably depends on their threat assessment.
Likely it wasn't due to the protests but because it overwhelmed whatever hardware they use for tracking individual targets in the area so it opened up a potential window for a nation-state to take advantage of the chaos.
China makes fun of him
And the Irish too