Indiana is closer to becoming a Right-To-Work state.
The Senate passed a measure that would prohibit unions from charging dues to non-members by a 28-to-22 vote.
Nine republicans and 13 Democrats voted against it.
There are currently 22-states with similar laws in place, but Democrats in the House are trying to stop the bill from moving forward.
Party members walked out of the session again Monday in an effort to halt the legislation.
They are pushing for it to be put on a referendum during the November election.