The Change to Win coalition of unions backed Barack Obama today. It's mostly symbolic in that most of the member unions already endorsed him.
The "but" is that two unions -- the Laborers and the Carptenters -- are staying neutral.
Writes Laborers President Terrence O'Sullivan in a statement:
"Senator Obama has proven himself to be a champion for working people and the membership of our union, as has Senator Hillary Clinton. We abstained from the vote in order to continue with our union’s endorsement process."