Presidential elections aren't a reliable litmus test. Congressional votes and "lesser" offices are where it is at. Based on the Q in the OP, well, I have been an adult a good long while and never have voted for a democrat president. Working our way back:
Obama - to me he represents
More of what is wrong and none of what would fix it.
Kerry - was an unacceptable risk to my 2A rights. His ties to the VPC, his ownership by corporations. . . . his military record. . . there just was NO way, none, I could have considered voting for him. I went with Bush because he was the lesser of two evils. .. eyes open, I realize and fully acknowledge that as evil as Bush is/was it was better than the alternative. Yeah, yuk. My angst over seeing how that played out was what led me to drop the Republicans. I just couldn't do that anymore, chooosing the lesser of two evils is still choosing evil.
Gore - Continues to embarass himself. Just plain laughable and always has been. Couldn't even really take him seriously as a canidate.
Clinton - Clinton AWB . . . for a gun rights advocate like me, need I say more. I didn't want him and he proved me right. Fortunately, that was a VERY expensive mistake for democrats in Congress and as the data panned out, that law really was a worthless piece of junk. I voted for Perot because I couldn't stomach Dole. Prior to that I had hoped G.H.B would have gone for round two.
That said, my congressional and other votes have been all over the place. I did vote for Al Franken.