It depends what you mean by "pledged"

I should have known this but I confess I didn't:

Hillary Clinton’s presidential campaign intends to go after delegates whom Barack Obama has already won in the caucuses and primaries if she needs them to win the nomination.

This strategy was confirmed to me by a high-ranking Clinton official on Monday. And I am not talking about superdelegates, those 795 party big shots who are not pledged to anybody. I am talking about getting pledged delegates to switch sides.

What? Isn’t that impossible? A pledged delegate is pledged to a particular candidate and cannot switch, right?

Wrong...

The notion that pledged delegates must vote for a certain candidate is, according to the Democratic National Committee, a “myth.”

“Delegates are NOT bound to vote for the candidate they are pledged to at the convention or on the first ballot,” a recent DNC memo states. “A delegate goes to the convention with a signed pledge of support for a particular presidential candidate. At the convention, while it is assumed that the delegate will cast their vote for the candidate they are publicly pledged to, it is not required.”

Since you can be "pledged" without being "bound", this surely raises the question whether you can be "bound" without being "required", or vice versa, or indeed whether you can be "required" without being "actually required", or "bound, in fact". Fortunately the party has a few lawyers on hand, so I'm sure the correct result will emerge in the end...but am I alone in thinking that this system leaves something to be desired?