Washington (CNN) The Wisconsin state Senate on Wednesday passed a "right to work" bill Wednesday, sending it for likely approval to the GOP-controlled state Assembly.

The proposal, which would let workers opt out of paying mandatory dues, is another blow to unions in Wisconsin after Gov. Scott Walker in 2011 helped pass a bill curtailing the rights of the state's public sector unions.

He won plaudits from conservatives for taking on the state's unions that year and ultimately surviving a recall attempt launched because of the move.

That 2011 fight catapulted him to the national stage and has contributed to his support in polls of the potential 2016 presidential race, where he routinely comes in the top four of the pack.

Supporters of the Wisconsin "right to work" law note that laws like it are sweeping the Midwest, and have already been passed in Michigan and Indiana. They say it will help make the state more competitive for business.

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