ST. PAUL — Minnesota Republican senators got a taste Monday of the fight over labor rights that gripped other Midwestern statehouses in the last year, with a committee narrowly passing legislation to curb union power even as hundreds of demonstrators chanted and yelled just feet away.

The Senate Judiciary Committee approved a constitutional amendment that would let voters statewide decide if Minnesota should be a right-to-work state, with voluntary union membership. The vote was 7-6, with one Republican joining the committee’s five Democrats to vote no.

Union members flooded the hallways outside the hearing room, waving signs. Protesters were loud enough that people testifying on the bill were drowned out by chants of “kill the bill” every time someone entered or left the room.

If the amendment were to pass the full House and Senate, voters in November would decide whether Minnesota’s Constitution should be amended to make membership voluntary in both private and public unions. Membership is not compulsory under current law, but non-union employees in most unionized shops are required to pay a “fair share” fee of up to 85 percent of normal dues.

The Senate committee’s action far from guarantees a statewide vote. Some legislative Republicans don’t want the issue on the ballot, knowing it would pick a massive political fight with unions. The bill’s chief Senate sponsor said he has no promise from his majority leader that the full chamber will take it up this year.