Why the Guardian is no longer posting on X

Yes, they are a UK publication. But they cover a lot of US news and have a significant American readership. So, like American newspapers, they have an informed opinion and an audience that wishes to hear that opinion.

That's how newspaper endorsements work. In this case the writer of the endorsement cannot themselves vote, but their opinion can still have weight.

The Economist, another UK-based periodical with a more right-wing stance, explains why it endorses candidates:

https://www.economist.com/the-economist-explains/2024/10/31/...

At least here in America, endorsement of foreign politicians is seen as election interference, and generally not done.

Newspapers don't generally do it, but I've never seen it as a matter of avoiding interference. Rather, it's just that we simply don't have much interest one way or the other in most elections. The newspapers don't spend a lot of time covering them and would not consider themselves sufficiently knowledgeable to make an endorsement.

The American election is special, in that it's the "leader of the free world". What we do here affects everybody, in a way that even the leadership of Germany, France, and England doesn't. Perhaps we'd have an opinion about the leadership in Russia or China, but they don't have free elections.

The government should probably refrain from making an endorsement, but if people can't figure out the distinction between a government and a newspaper, that's their own lookout.