Jim would've been in California on June 4, 1968, and I would not be at all surprised if he voted for Robert Kennedy in the California primary that day, hours before Kennedy was murdered.
Jim might not have voted in the 1968 presidential general election for the simple fact that he may well have been out of town. The Doors were in the middle of their Midwest Tour when the election took place on Tuesday, November 5: Louisville, October 31 (Halloween); Milwaukee, November 1; Columbus, November 2; Chicago, November 3; Phoenix, November 7; Madison, November 8; St. Louis, November 9; Minneapolis, November 10. Maybe they came back to California between the 4th and 7th, maybe not. If not, Jim didn't have a ton of time to have obtained an absentee ballot, given that he was in Europe through September to October 20.
If he did vote in that election, I have a hard time imagining him voting for Nixon and his running mate, Spiro Agnew, who were openly and vocally contemptuous and hostile toward drugs, protest, long hair on men, anyone against the Vietnam War, rock, etc.
The 1968 presidential election was extremely close, and Humphrey had a lot of momentum in its closing weeks. Most experts, and polling, agree that had the election been held a week or so later, Humphrey would almost certainly have won.
I think you're right. Jim and I talked politics a little, but he didn't specify how or even if he'd voted, and neither did I.
But there's no way in hell he would have voted for Tricky. Nixon was out to get him--that was very clear--and it's become even more clear to me over the intervening years:
that Dick Nixon killed Jim Morrison.
I don't mean it literally, but Nixon played a major part in the Miami fiasco. He was pulling the strings behind the scenes. Nixon was paranoid, and Jim had said something about "getting him" if he didn't perform and that was all it took. Jim was in the presidential gunsites from then on.
Oh, and by the way--Happy Birthday, Jimmy Doug. Love you!