I have a letter signed by Senator Bill Bradly (D, NJ) However, it is probably worth more (and not that much either) because he was an NBA star rather than because he was one in an endless line of RAT party NJ senators (even if he was far from the worst of them).
I have a letter signed by Senator Alan Kittleman, of the Maryland state Senate. I don’t think it’s worth much though, otherwise I would’ve sold it long ago.