Yes. I think he left his brain on orbit. I had trouble reconciling "Heroic Marine Aviator and Astronaut John Glenn" with "Dirtbag Politician John Glenn". The only thing I could figure was that something catastrophic happened in between NASA and the Senate, and changed him permanently and for the worse.
As Reagan said, politics is the second oldest profession. It's hard to go into it and stay clean. Glenn's ultimate ambition I believe was to be President (isn't it every Senator's?). Probably ran as a Dem because it was simply the easiest path to getting to the Senate.
Regardless of all that, RIP to a great American!