SB 3, the bill banning the sale and manufacture of every gas-operated semi-automatic firearm that can accept a detachable magazine, is scheduled to hit the floor of the Colorado State Senate today, and though Democrats appear to have the votes to send the bill to the House for consideration, today's session is still likely to have a lot of drama... and maybe even a surprise twist or two. 

In addition to the attempt by Republicans (and a handful of Democrats) to defeat the bill outright, expect to see a flurry of proposed amendments debated alongside the underlying bill. I'm also watching to see if there'll be any last minute defections... or rather, any more Democrats distancing themselves from SB 3 before a vote is held. 

A Democratic state senator who signed on as a cosponsor of Senate Bill 3, which would ban the manufacture and sale of certain semiautomatic rifles, shotguns and handguns that can accept detachable ammunition magazines, says he will vote against the measure. 

Sen. Marc Snyder of Manitou Springs said he didn’t fully understand its effect when he agreed to attach his name to it.

Snyder’s reversal doesn’t mean the legislation won’t pass. It still has enough supporters in the Senate to clear the chamber, barring more than one other defection. The bill is scheduled to get a preliminary vote in the Senate on Friday.

But it highlights the shifting political ground beneath Senate Bill 3, which would represent one of the biggest changes to Colorado gun policy in state history. 

Of the 23 Democrats in the chamber, 19 have either verbally committed to voting “yes” on the bill when asked by The Sun or have signaled they will support it by serving as cosponsors.

Two Democrats — Snyder and Sen. Nick Hinrichsen of Pueblo — say they can’t vote for the measure as is, while two more — Sens. Dylan Roberts and Kyle Mullica — haven’t said how they will vote on the legislation. 

Gun owners in Colorado need to keep up the pressure, especially since some cracks are emerging in the anti-gun firewall in the Senate. One of the reasons Snyder gave for his about-face was the fact that his constituents "overwhelmingly oppose" gun bans, so the contacts by Colorado 2A advocates appears to be having an impact. 

Though existing gun owners would be grandfathered in and allowed to keep the gas-operated semi-automatic firearms they currently own, SB 3 would still be the most extreme and extensive gun ban in the country if it becomes law. All gas-operated semi-automatic rifles, shotguns, and pistols sold in Colorado would have to come with a magazine permanently attached to the firearm, which would place almost every semi-automatic long gun off-limits to residents going forward. 

The sweeping semi-auto ban is the top priority for the gun control lobby this year, and not just in Colorado. Similar bills are being pushed in New Mexico and Rhode Island as well, and gun control activists rallied in support of the ban at the New Mexico capitol building earlier this week. 

Barring any more last minute defections, SB 3 will probably pass the Senate, but not without a fight. Colorado Gov. Jared Polis is also still non-committal about signing SB 3, so gun owners shouldn't throw in the towel and accept SB 3's passage as inevitable. There's a good chance the bill get watered down as it makes its way through the legislature, and its outright defeat still isn't out of the question. 

If SB 3 does become law it will face an immediate court challenge, but it's always better to defeat a bad bill than to try to overturn a bad law, and today might be the best chance of killing the bill before it gets to the governor's desk.