Eliza Collins

USA TODAY

For nearly 15 hours, Senate Democrats about guns. The group took over the Senate floor to talk about gun control in the wake of the massacre in Orlando Sunday that killed 49 and injured 53 others.

This has all the making of a filibuster, but it’s not the usual filibuster. Usually, a filibuster refers to a senator trying to stop the chamber from voting on a bill. In this case, there was no bill being considered. So the Democrats are just filling what would otherwise be empty time to draw attention to the cause. Still — the Senate can’t move on to anything else as long as they stick to it, so — maybe we create new category: A “filiGUNster.”

Here are the big things to know about the crew who have taken over the Senate floor:

When did it start?

11:21 a.m.

Who pulled this thing together?

Connecticut Sen. Chris Murphy announced on Wednesday that he would talk “for as long as I can” about “the need to prevent gun violence.” Murphy has been an outspoken gun control advocate after the 2012 shooting in a Newtown, Conn., Elementary School left 20 children and six adults dead.

But it takes a village. Immediately after Murphy started, fellow Connecticut Sen. Richard Blumenthal and New Jersey Sen. Cory Booker joined in. Others who have lent their voices? Massachusetts Sens. Elizabeth Warren and Edward Markey, Oregon Sen. Jeff Merkley, Ohio Sen. Sherrod Brown, Maryland Sen. Barbara Mikulski, Minnesota Sen. Amy Klobuchar, Michigan Sen. Debbie Stabenow and more.

Which measures are they focusing on?

California Sen. Dianne Feinstein introduced a proposal that would allow the attorney general to ban gun sales to suspected terrorists, including those on watch lists, if there is “reasonable belief” the weapons may be used to carry out an attack. And it’s gotten new life after the attacks in Orlando because the shooter had been investigated by the FBI twice but was still allowed to buy guns.

There’s also a Republican version of this, because isn’t there always two sides? Texas Sen. John Cornyn has proposed a measure that would require the Justice Department to go before a judge and prove probable cause before banning someone from buying a gun.

Realistically, the chances of either bill passing are slim. They’ve both been voted on before — and lost.

What are the presidential candidates saying about it?

You didn’t really think there would be a story without the election being mentioned now did you? The presumptive Republican nominee tweeted Wednesday morning that he would be meeting with the National Rifle Association “about not allowing people on the terrorist watch list, or the no fly list, to buy guns.” The NRA quickly sent out a statement of their own that said they’d meet with Trump but they weren’t changing their position and they backed Cornyn’s bill.

Meanwhile, unsurprisingly, the presumptive Democratic nominee supported the Democratic senators. Clinton has been calling for legislation on the gun sales to suspected terrorists and those on no-fly lists and she gave props to Murphy via Twitter: “Some fights are too important to stay silent. Preventing gun violence is one of them. Stand strong @ChrisMurphyCT.”

Donovan Slack and Paul Singer contributed reporting.