The Dems actually have some history of blocking majority supported gun control bills:
Senator Chuck Grassley proposed legislation that would have increased funding for the NICS background check system, and would have pressed states to send more records to the FBI on felons and others barred from buying guns. It also revamped language that prohibits some people with mental health problems from buying guns. Grassley’s bill had majority support, 53-47, but
wasn’t passed because the Democrats filibustered it.
Senator John Cornyn offered legislation to keep firearms out of the hands of suspected terrorists. His bill would let the government block a sale to a known or suspected terrorist, and prosecutors would then have three days to convince a judge that the would-be buyer was likely a terrorist. This seems like a sensible compromise, and it too had majority support, 53-47,
but again the Democrats filibustered and blocked the bill from taking effect.
The Democrats likewise offered two proposals, both of which enjoyed less support. Dianne Feinstein proposed legislation that would bar gun sales to people on any federal terrorism watch list–a list that has included Ted Kennedy, Nelson Mandela, and many random, innocent citizens–without providing any way for people to get themselves taken off the list. I think it is safe to say that this proposal was sheer political grandstanding. It went down to a 47-53 defeat. It is shameful that so many Democrats voted for it.
Chris Murphy’s bill would have required the current, inadequate list of people who can’t buy guns to be applied to even more sales, including sales between friends or relatives. That, too, was defeated 47-53.
http://www.powerlineblog.com/archives/2016/06/democrats-block-sensible-gun-proposals-in-senate.php
Dems would rather grandstand than pass any bipartisan measures.
Senate Minority Leader
Chuck Schumer (D-N.Y.) signaled on Tuesday that his caucus may block the modest bipartisan proposal to improve — but not expand — background checks for gun purchases unless Republicans commit to voting on broader gun control measures.
...
“
Rather than just passing one narrow bill and moving on, we Democrats intend to push our Republican colleagues to have a real debate on gun safety,” Schumer added.
https://www.politico.com/story/2018/02/27/congress-guns-background-checks-bill-429509
More grandstanding, likely to keep it an issue for the midterm rather than get even modest gun control. Endless debate instead of any action at all.
Why didn’t Democrats curb gun laws when they controlled Washington from 2009 to 2010?
“Yes,” Sen. Bill Nelson (D-Fla.) said Wednesday when asked by CNN’s Jake Tapper if his party made a mistake in not acting. “When the Senate had 60 votes, as we did until Ted Kennedy died, that’s how we got the Affordable Care Act passed.
And, yes, gun legislation under those circumstances should have been considered because there’d been a lot of massacres up to that point.”
https://www.washingtonpost.com/news...y-controlled-congress/?utm_term=.fabdde11babe