In WA last year, a basic anti (not rabid) democrat gov signed a bill to allow legally held silencers in WA State...repealing part of what another (rabid) anti demo govenor had banned them (and other NFA items) in 1994)
The argument that won...Hearing damage.
Bill 1016 allowed the use of registered silencers on firearms. Use was banned back in the 1930's, not in 1994. The 1994 ban was SBS and SBR. The police and military were not allowed to use silencers either although it was "common knowledge" that they were exempt from prosecution by the AG. When I wrote to the AG requesting the same exemption I was told that no such exemption existed.
After hearing this I let every police officer I saw know it. I was also present and speaking at the House Judiciary Committee hearing when Brian Wurst, a WACOPS representative spoke out in support of the bill. His major points were hearing protection.
I think what made the bill pass was that there was very little silencer associated crime in WA and no evidence that any used in crime were registered. Even "anti-gun nut" Senator Adam Kline urged the Senate to show bill 1016 "a lot of love" on the Senate floor. In my opinion this was not done out of a desire to see the bill passed, but that he knew passing the bill would not affect WA crime at all and it was a chance for even the anti-gun legislators to look good to their gun owning constituents and at the same time not look bad to the anti-gun people in their district. It is likely that very few people knew about the bill passing anyway.