Yes. There are laws governing poll watching.
Trump supporters and their professed antics violate them.
I think some of them are in for a big surprise when they find out that they can’t, at least in most places and unless they are a registered poll worker, just waltz into the polling place and start crap, especially if they are going to challenge voters based on race or ethnicity.
Poll observers where allowed are just that, observers. They can report irregularities but are not supposed to interfere with the voting.
They also need to be aware if they are going to be outside, every jurisdiction has rules for how far away from the door they must be. And doing things like taking photographs of people going into or coming out of the polling places or asking people who they are voting for so as to keep their own tally, as I’ve seen suggested, could also get them in trouble.
I hate being hassled by anyone on my way in to vote, even if they are electioneering for a candidate I plan on voting for. I park and will then walk in such a way as to not get anywhere near them. I don’t want their pamphlets or hear their spiel. I’ve already made up my mind and want to get in and out as quickly as possible.
I don’t even take one of those “I Voted” stickers. I guess that makes me a curmudgeon. ^-^ ^-^