Those guys are senators. There are no voting districts for Senate elections. They are state-wide popular votes.

Voting districts are relevant at the federal level for presidential and House of Representatives races.

I use the Mistel Barocco MD600. They have windows-only software but I’ve never used it. You can program everything on the keyboard itself.

It works great for me on Mac and Linux with separate key map/macro layers. I’m also a fan of split keyboards so that’s an added benefit.