Favorite daughter?

Not so much, it seems. At least, Hillary Clinton's not the favorite candidate of some New York City unions. First the Transit Workers Union, representing 30,000 New York workers, endorsed John Edwards. Now another New York union, the 9,000 strong Correction Officers' Benevolent Association, is lining up behind Obama.

Her campaign has developed a mistake-free aura, but little slips like this on the home front might betray some chips in the seemingly impenetrable Clinton armor.

Or not. I don't know what the internal dynamics of the unions' internal processes were, or Clinton's history with them. It's something worth watching, though.