Even the Pledged

Pr. George’s Executive Switches To Obama
(Rosalind S. Helderman, Washington Post)

“I cannot in good conscience go to the convention and not support Barack,” Johnson said in an interview. “She ran a great campaign, but she fell short of the line.”

…

Unlike superdelegates, who are free to endorse either candidate, Johnson is one of 28 pledged delegates who have agreed to represent the 36 percent of Maryland Democrats who voted for Clinton on Feb. 12.

(via 2008 Democratic Convention Watch)

The Democratic Convention Watch article has some additional analysis on how Clinton ended up with a faithless pledged delegate. (It looks like thier screening process was a bit flawed, he had actually declared for Obama originally, then changed his mind to Clinton, and is now changing back… the campaigns normally pick their pledged delegates based on unwavering solid loyalty and commitment. Oops.)