By Jon Frandsen, Senior Editor March 25, 2009 Labor's top legislative goal -- a card check-off system that would make organizing non-union businesses easier than full-scale secret-ballot elections -- is in serious trouble. Sen. Arlen Specter, R-Pa., one of the few Republican supporters of the measure in the past, says he won't join Democratic efforts to cut off debate when the bill comes up. That seems to leave the Democrats a vote short. Specter is a moderate Republican who is constantly in the sights of conservatives for voting with Democrats on too many issues -- most recently in favor of the stimulus bill. His shift on card-check off could help him fend off a conservative challenge in his bid to win a sixth term next year.But any effect the move may have on Specter's political future may be dwarfed by the blessing it bestows on Democrats. Politico points out that keeping the measure from a final vote might save Democrats from a bruising fight that could alienate labor, a crucial element of it's political and financial base. Some moderate Democrats oppose or lean against the measure and being spared a difficult vote would mean not having to take sides on an issue that is just as bitterly opposed by business as it is favored by labor unions. The prospect of ducking the issue is bound to be a relief to President Obama, too. He favors the bill but has avoided making it a legislative priority because of its divisiveness. Another option that might look more attractive to labor is compromise. Obama has indicated he is open to that and some business leaders are pushing one. So far,labor has been unwilling to bend, but the loss of Specter could make them feel that half a loaf is better than nothing.