After decades of both declining numbers and political clout, the nation’s biggest labor federation is branching out.

At the AFL-CIO convention in Los Angeles Monday, leaders opened the doors to millions of non-union workers with an invitation:

“The AFL-CIO hereby invites every worker in the United States to join the labor movement”

That’s right– the federation has opened the representation door for the first time to millions of non-union workers.

But there’s a catch.  Collective bargaining isn’t a part of the new deal.

So will this “diet” version give labor back its clout?

“Certainly if they can organize enough workers outside of collective bargaining, they will increase their influence because this is also a political voting block,” says Northeastern University economist Barry Bluestone.

That’s good for the labor movement, but not so great for struggling workers.

“These workers all want collective bargaining, all need collective bargaining,” says Cornell’s Kate Bronfenbrenner.

Without the power of collective bargaining to push companies, it’s not clear how many workers will take up the labor group on its invitation.