Britain's vote to leave EU passes with ~51.8%

Just FYI, this is not 100% true. Many states require delegates to vote according to their constituents for things like presidential candidates.

Right, state level stuff can override it, but the state actually has to say it outright or the delegates don't technically have to do it. Superdelegates are not bound by anything though, they can vote for whoever they want no matter what the law says. Luckily, they are only a thing in the Democratic primaries, Republicans don't use that pomegranate and they aren't used in the general either.