If you're actually interested in the topic, google for a bit and you'll learn that is an old advice.

Here's a post about it: https://www.barrypopik.com/index.php/new_york_city/entry/nev...

Many cultures frown on turning dinner time into debate time. It's been that way for generations. They talk about politics among family and friends or people with similar opinions.

Americans still talk about politics over dinner.

This advice is more about protecting Europeans from an uncomfortable experience on vacation because of exposure to political views they will find objectionable, than about some fundamental inability to talk about politics in the U.S.

I'm exposed to political views I find "objectionable" just by talking to my parents. You put five of my family into one room, and we'll be voting for six different parties. If everyone agreed there wouldn't be much to talk about.

Though calling political views you disagree with "objectionable" as in "offensive" is starting on the wrong foot already. You can't convince someone of your POV by acting offended.

Where is this travel advice coming from? It sounds like typical cultural ignorance to me. I'm American and (when I lived there) would have no qualms talking about politics with seemingly everyone regardless of meal time. There are certainly some people who will have a stronger response these days due to increased polarization, but if you speak sensibly and thoughtfully it's difficult to see it becoming an issue.

I dunno, seems consistent with my experience in the midatlantic/northeast. politics is absolutely on the table with close friends and my family. outside of that, I find people usually avoid discussing politics unless they are confident everyone else present already agrees with them.