As someone who was pretty hard on the Clinton campaign's on-again, off-again plan to pressure Barack Obama's pledged delegates to switch sides, let me say I don't like it any better when the shoe is on the other foot. From TPM:
Jack B. Johnson, the executive of Prince George's County, Maryland, was elected as a pledged delegate for Hillary in the February 12 primary. However, he now says Obama has won the nomination, and he will support him at the convention: "I cannot in good conscience go to the convention and not support Barack."
Now, as far as I know, the Obama campaign didn't court this defection. And it's not hard to see why Johnson would be inclined to switch: His county, after all, voted about 80 percent for Obama in the Maryland Democratic primary. (One would think this would have made him a very poor choice to represent Clinton as a pledged delegate.) And, as folks on the Clinton campaign noted on several occasions, there is no legal bar to pledged delegates switching their votes.
But there is, or ought to be, a moral one. There may be extraordinary cases in which it is reasonable for a pledged delegate to defy the will of the citizens whose votes he's representing, but this isn't one of them. There have been plenty of procedural absurdities that have been brought to light in this year's extended primary. But none come close to comparing with the undemocratic chaos that would ensue if other delegates took their pledges as lightly as Johnson does his.