I don't see the big problem, I mean a lot of people want a fence around their yard and if the previous owners didn't have one I can see why they would get started on the project as soon as possible as summer is coming soon. If you were the only other person on the street then maybe you could take this the wrong way, but I don't think there's anything more to it than just wanting fence, whether for an animal, privacy, safety or aesthetics.

they must be Trump supporters

Talk about building walls instead of breaking them

Fences make good neighbors.

I wouuldn't take it to heart, many people just want privacy, so it was probably unrelated to you.

Was it Donald trump?

Looks like I arrived too late to make a Trump joke...

What if they just wanted a fence? What if they have a dog or something?

Don't worry, op. My wife and I just moved into our new home about a month ago, met our neighbor, and put up a "living fence" (trees) along the sides of our deck. We had planned to get the trees even before we moved in, so to our neighbor it probably felt like you did, but to us, we felt like we'd waited two months to put the "fence" up. We just like our privacy, nothing to do with who our neighbors are at all :) (read: we just want to get naked on our deck without our immediate neighbors seeing!)

They're prolly voting for trump