First, some premises:

1) No candidate is perfect.  Even if you think you're 100% in line with their positions, they will disappoint you at one time or another.

2) Neither Obama nor Clinton are "squeaky clean".  It's unfortunate, but probably at least partially accurate to say that they wouldn't be where they are now if they were.  No, I'm not suggesting that either candidate did anything illegal, but they both have engaged in things that are probably not of the highest moral fabric.

3) There are lots of supporters from BOTH camps who support their candidates for potentially stupid reasons.  Whether it's a woman who votes for Hillary simply because she's a woman, or an African American who votes for Obama simply because he's black, or any number of other stupid, selfish, racist, sexist, ageist, or whatever reasons people may have, they still have it.

4) There are lots of supporters from BOTH camps who support their candidates for possibly even stupider reasons than probably you or I could even imagine, which were not included in the previous point and which may amount to not much of a reason at all.  Even so, it's a reason to THEM, and they're a citizen 18 or over, and, under our current laws, have a right to vote.

5) While there are policy differences between candidates, they are fairly similar and, in the end, vastly better than any Republican candidate, particularly in picking Supreme Court justices (a HUGE issue considering the more liberal bloc on the court is aging and appointments are for life).

Ok, still with me?  If so, with that in mind, here's my pledge:

1) I will support whoever the nominee is from the Democratic party (assuming there are, of course, no crazy changes and it ends up being someone like Lieberman or the like, in which case I'd really have to think about it again).

2) I will not focus my attacks on the SUPPORTERS of the Democratic candidates.  I will not collectively insult their ability to make decisions or process information.  I will engage people on the merits or demerits of the candidates and their policies, and not assume that the candidate's supporters don't have minds of their own.  Agree or disagree, they have their reasons for supporting their candidate, and I have mine.  

3) I will not gloat if my candidate wins the nomination, no matter the circumstances.

4) If my non-preferred candidate wins the nomination but loses the general election, I will not say "I told you so" to the supporters of the general election loser, as, barring the invention of a time machine, there is really no way to know how the other candidate would have fared in the same election.

That's all I can think of for now.  Will you support this pledge?