Union members by the hundreds filed into the state Capitol on Monday morning as a group of Senate lawmakers discussed a proposed constitutional amendment that would make it harder for unions to organize. Critics of the bill say it would lower wages and cut benefits for middle-class families. Supporters say it would help businesses create new jobs.

As Minnesotans observe the Labor Day holiday, statistics reveal the number of union members in the state continues to erode. At its peak in 1992, the rate of union membership in Minnesota was at 22 percent. In 2011 it was at 15.1 percent, down from 15.6 percent in 2010.

The Senate Local Government and Elections Committee passed the voter ID bill on a party-line vote, with DFLers opposing it. The measure has several more stops before it would appear on the November ballot as a proposed Constitutional amendment.

Union-weakening legislation in several Midwestern states has lost momentum since swarms of protesters mobbed Indiana's capitol after a right-to-work measure passed there. While some Minnesota Republicans still want to pursue a Constitutional amendment, others are leery of the prospect of busloads of protesters at the Capitol and an energized union vote at the polls.

Over the chants of hundreds of union members opposing the bill, the committee passed a measure that would put the right to work issue on Minnesota's ballot in November. 23 states have enacted similar laws that make union membership voluntary, rather than compulsory.

A legislative commission voted to hire a private law firm to defend the voter ID question lawmakers put on this fall's ballot. Next month the Minnesota Supreme Court will hear arguments in a lawsuit that claims the ballot question does not accurately describe the Constitutional amendment that would require an ID to vote.

The constitutional amendment would not allow contracts to require employees to join unions or pay dues. Sen. Dave Thompson of Lakeville continues to stress the measure will not impact collective bargaining in Minnesota.

The marriage amendment may not be the only proposed Constitutional amendment put to the state's voters this year. Republican lawmakers are considering ballot questions on other issues. Those include needing an ID to vote, needing a supermajority to pass a tax increase, and making union membership voluntary.