Everywhere A Sign

I was recently walking by a house with a sign in the yard that contained a bunch of political slogans, including "No human is illegal" and "Science Is Real."

Let's ignore that these are trendy, mindless phrases that don't really say anything beyond letting people know what side you're on.

Here's what I want to know.  Why would any people feel the need to put up such a sign? Are they worried that passersby will walk down the sidewalk thinking "I wonder if the people inside this house have their minds right on immigration?--their stance isn't certain so I'm going to assume evil things of them."

Do these people actually believe this will convince anyone of anything beyond the fact they've got an obnoxious sign in their yard announcing their politics?

It might be fun to live across from them and put up your own sign, saying--I don't know, how about "signs are stupid." And when they tear that down, put up "vandal are intolerant despite what their signs might lead you to believe."