Tonight, Senate Democrats made good on a commitment they had little leverage until now to follow through on: a promise to take votes on gun control bills.

They still didn't have the leverage, however, to pass them.

After the worst mass shooting in modern American history, a 15-hour Senate Democratic filibuster led by Sen. Chris Murphy (D-CT) shamed Republicans into scheduling votes for Monday.

But Monday night, the Senate failed to reach the 60-vote threshold for cloture on any of four separate measures: Republican and Democratic versions of a bill addressing background checks failed to reach the 60-vote threshhold for cloture; so did the Republican and Democratic versions of a bill restricting "suspected terrorists" from being able to buy guns.

The proposals were offered as amendments to an appropriations bill covering the departments of Commerce and Justice, as well as science and other agencies.

But the most interesting thing for the long-term prospects of gun control is that the votes happened at all.

Since the filibuster last week, Democrats have marched in lockstep to portray Republicans as too dogmatic on gun control to tackle a national security crisis. As a result, they’ve put Republicans on defense, forcing them to come up with objections to Democratic proposals and alternatives of their own, and putting former supporters of gun control in tough races (like Sen. Pat Toomey) in an especially tricky position.

When it came time to vote, Republicans mostly closed ranks — with one notable exception. But the debate around the issue indicates that Democrats are still united, and Republicans are struggling to play defense.

The Senate voted down two amendments that would have expanded background checks for gun purchases

In the wake of the 2012 Sandy Hook massacre, Democrats (and a few Republicans) pushed for a bill that would require background checks for all gun purchases — including those between one private gun owner and another (what gun control advocates call the "gun show loophole").

That proposal failed, but it’s still close to the top of the gun control agenda; President Obama issued executive orders regulating some gun show sales earlier this year, and Senate Democrats are taking another stab after Orlando.

Sen. Chuck Grassley’s Republican version: failed to pass cloture, 53-47. Sen. Grassley (R-IA), the chair of the Senate Judiciary Committee, reintoduced a version of the same background check alternative he introduced during the 2013 fight. Grassley’s version wouldn’t expand the use of the background check system — instead, it would expand what’s currently included in it.

In particular, the amendment would encourage states to submit some mental health records to be included in the system. The National Rifle Association has long complained that privacy laws currently prevent this; the proposal was in line with the general opinion of gun rights advocates that mass shootings represent a mental health problem rather than a gun problem.

At the same time, though, the amendment would make it harder for the VA to prevent veterans from buying guns on mental health grounds — something that Grassley and other Republicans have complained about the Obama administration doing unilaterally.

Sen. Chris Murphy’s Democratic version: failed to pass cloture, 44-56. The Democratic proposal, a version of the 2013 "Manchin-Toomey" background check bill, was pretty straightforward: It would require background checks for all firearms sales by private sellers, including at gun shows and over the internet. The Democratic plan also had provisions to bolster the records kept by the background checks system.

The bill wasn’t identical to the 2013 version, however — it’s more restrictive. So the Senate GOP attacked it as "intentionally partisan," and Toomey didn't support it.

They also killed two amendments to close the "terror gap" by allowing the government to block gun sales to suspected terrorists

Spurred by a 15-hour filibuster led by Sen. Chris Murphy last week, Democrats want to give the federal government veto power over firearm sales to protected terrorists.

Republicans, concerned that the Democrats’ plan would give the executive branch too much power to crack down on Second Amendment rights, proposed a competing proposal that would ensure judicial oversight — something that Democrats have attacked as impractical.

Neither succeeded.

Sen. John Cornyn’s Republican version: failed to pass cloture, 53-47. Both the Democratic and Republican plans would allow the federal government to deny someone the ability to buy a gun on the grounds that he’s suspected of terrorism — something federal law currently doesn’t do.

But what Senate Majority Whip John Cornyn (R-TX) and the NRA wanted to do was to force federal authorities to prove in court that there’s "probable cause" that the gun buyer will commit an act of terrorism. Under Cornyn’s proposal, the government would also only have 72 hours to file the paperwork to do so.

Democrats said the bill would create unreasonably onerous requirements for the executive branch — that the government simply wouldn’t have the capacity to produce the necessary evidence or do so within the three-day time frame.

Sen. Dianne Feinstein’s Democratic version: failed to pass cloture, 47-53. The Democrats’ proposal would give the Department of Justice broader authority to block gun sales to suspected terrorists — without requiring its decisions to be approved by a judge, or anyone else.

Under Feinstein’s proposal, the federal government would give greater scrutiny to any gun purchase from someone on the "terrorist watch list" or anyone who’s been investigated in connection with terrorism over the past five years.

To block the sale, the government would have to have reasonable suspicion that the person represented "a threat to public safety" and was considering or engaging in terrorist activities. (Here’s the exact wording from the amendment on what a "threat to public safety" would entail.)

Unlike Cornyn’s bill, however, Feinstein’s proposal didn’t create a mechanism for judicial review. And for that reason, it was opposed not just by Republicans but also by civil liberties groups and some liberals who fear that it would strengthen some of the most opaque and easily abused powers the government has acquired in the name of the war on terror.

How fast 4 different guns can shoot and reload