Here's how this works..... Looking back over the presidential elections in which you had a preference (whether you actually voted or not), are there any candidates you now wish you hadn't supported or any candidates you now wish you had supported instead? You can answer either way or both.
Because I've voted for a lot of 3rd party candidates, there are none on my list that I wish I hadn't voted for. But if I had to do it over again now, I'd probably vote for Carter in 1980 instead of Anderson. Wouldn't have made any difference, of course, but I think I was too hard on Carter.
1968 -- the first year I was eligible to vote, I didn't. I regret that. I thought Nixon was a less disastrous choice than the Hump -- I really thought we might have a low-grade revolution if the Hump were elected -- but I knew Nixon was going to carry Iowa and I couldn't bring myself to actually go and vote for the s.o.b. The only other race I would have voted in was the Senate, and my candidate -- Hughes -- was going to win easily, so he didn't need my vote. If I had it to do over, I probably would vote for Nixon, just so I didn't have to admit I refused to vote the first time I had a chance.
1972 -- I voted for McGovern. If I had it to do over again, I'd have voted for somebody else. Not Nixon, though. It was a throw-away vote because the election wasn't competitive.
1976 -- I voted for Carter. Definitely would go for Ford if I had a mulligan. Carter was a disaster. I was mostly voting against Ford as a protest for pardoning Nixon, but I also had high hopes for Carter. Got all misty-eyed when he got out of the limo and walked up the street during the inaugural parade.
1980 -- Only time I voted absentee. Was in a hospital bed. Thought Carter was a disaster, but hadn't completed the maturation into a conservative. Mrs. LC, a radical liberal in her earlier years, was much better informed than I, and had done so. She brought me the absentee ballot. I said, "You promise that Reagan won't start a nuclear war?" and she assured me on that score, so I voted for him. Would do so again.
1984 -- Gipper again, no problem.
1988 -- Bush 41 again, no problem.
1992 -- Bush 41 again, no problem.
1996 -- Would probably write in somebody's name. Voted for Dole, and I have great respect for him and his service, but a vote for somebody else might have made me feel better.
2000 -- Bush 43 again, no problem.
2004 -- Bush 43 again, no problem.
2008 -- McCain, because I thought Obama wasn't up to the job, but I held my nose. I think if Romney had been the candidate, he would have won, thanks to the financial meltdown in the months before the election.
2012 -- Romney, no problem. Obama was much, much worse than I had feared.