Senate Majority Leader Chuck Schumer could bring a bill to ban bump stocks to the floor for a vote as early as today, seeking unanimous consent to prohibit the sale and possession of the devices. 

It only takes one member of the upper chamber to derail a unanimous consent vote, and according to NBC News there'll be at least one member of the GOP caucus rising to object.

He [Schumer] said Democrats will ask the Senate for unanimous consent for legislation by Sen. Martin Heinrich, D-N.M., called the BUMP Act, which would revise the U.S. criminal code to prohibit bump stocks.

The Trump administration initially put the regulation in place with the support of many Republicans. But Trump and some of the GOP lawmakers who backed it have now expressed less interest taking legislative steps to prohibit the accessories. 

Any senator can deny a unanimous consent request. Sen. Lindsey Graham, R-S.C., told NBC News he will block the measure, meaning it would not be able to move forward under the expedited process.

“I will oppose any legislative fix,” Graham said Monday.

Once Schumer's bid for unanimous consent fails, the next move for the Democrats will almost certainly entail holding a roll call vote on the BUMP Act, putting every senator on record in support or opposition to the ban. Schumer would need nine Republicans to join with Democrats in order to pass the ban, and while one of the squishiest members of the GOP caucus has already come out in favor of Heinrich's bill, finding eight others eager to join him is going to be tough for Democrats.  

Sen. Chris Murphy, D-Conn., an outspoken proponent of tougher gun laws, said senators should support the measure banning bump stocks, calling it a “moderate proposal” that Republicans should have no problem voting for.

“Is it good politics to make it easier for potential mass killers to get their hands on machine guns? Probably not,” he said. “The idea is to try to make this attractive to Republicans. And we would be a lot better off if psychopaths couldn’t get their hands on machine guns. Let’s see if we can get a consensus this week. So I’ll be talking to Republicans all week to see if we can scrounge it up.”

At least some Republicans favor the bump stock ban, including Sen. Mitt Romney of Utah, who suggested the measure could come up through the normal process, requiring 60 votes to advance.

“I do support banning bump stocks,” he said. “I hope we can get a chance to vote on that.”

The Supreme Court just told us that bump stock-equipped rifles aren't machine guns under the federal definition, but that won't stop Murphy and every other Democrat from falsely claiming that SCOTUS just legalized machine guns. They have a vested interest in convincing the public that rejecting a bump stock ban would be the Second Amendment equivalent to passing an abortion law without an exception for the victims of rape or incest; something that may poll well within Republican circles, but finds far less support among independents and Democrats. 

If Republicans do end up shooting down the bump stock ban, it won't just be Chris Murphy blathering about psychopaths armed with machine guns. That will become one of the standard talking points for Democrats on the campaign trail between now and November. Heck, it's already started. 

Sen. Jacky Rosen, D-Nev., tore into Sen. JD Vance, R-Ohio, on Monday over remarks he made about bump stocks as the Senate grapples with whether to ban them.

Vance, who is widely considered a vice presidential contender on the GOP ticket with former President Donald Trump, called efforts by Senate Majority Leader Chuck Schumer of New York and other Democrats to ban the devices “a huge distraction.”

“I think that we have to ask ourselves: What is the real gun violence problem in this country, and are we legislating in a way that solves fake problems? Or solves real problems?” Vance told reporters. “And my very strong suspicion is that the Schumer legislation is aimed at a PR problem, not something that’s going to meaningfully reduce gun violence in this country.”

Vance also said he was concerned the bill could “end up just inhibiting the rights of law-abiding Americans.” Pressed about the 58 people who were killed in a mass shooting in Las Vegas in 2017, he said: “The question is: How many people would have been shot alternatively? And you have to ask yourself the question: Will anyone actually not choose a bump stock because Chuck Schumer passes a piece of legislation?”

His comments drew a fiery response from Rosen, who faces re-election this year. The Las Vegas gunman used firearms equipped with bump stocks.

“This is not a fake problem,” she told reporters. “Let him come to Las Vegas. Let him see the memorial for those people who died. Let him talk to those families. It’s not a fake problem. Those families are dead.”

“Las Vegas was changed forever because of what the shooter did, and the bump stocks helped him. And let JD Vance come — and I’m going to take him to the memorials. We’re going to talk to — talk about our first responders, our ambulance drivers, our police, our firefighters, people at the blood bank, regular people. Shame on him. Shame on him for disrespecting the dead,” the normally mild-mannered Rosen said in a rare flash of anger.

It's not disrespecting the victims of the Las Vegas shootings to point out that many people still would have been killed if a bump stock wasn't used. You could even argue that Rosen is exploiting the dead by demanding a bump stock ban in their name. 

From a pure 2A standpoint, opposing a bump stock ban makes sense. If we're just looking at the text, history, and tradition of the Second Amendment, even bans on actual full-auto firearms are pretty clearly unconstitutional. From a political perspective, however, the issue is a little messier for Republicans. Vance is absolutely right that bump stocks aren't a big problem when we're talking about crime and public safety, but Democrats are intent on making it a problem... for Republicans in Congress at least.