A bipartisan group of senators hoped to unveil a gun control deal on Friday, in the wake of a string of mass shootings, including those in Uvalde, Texas, and Buffalo, New York. They don’t have one yet, but negotiators are still cautiously optimistic about getting an agreement in the coming days.

“It’ll be a miracle if we get a framework agreement, never mind a final bill,” Sen. Chris Murphy (D-CT) told reporters on Thursday. “But miracles sometimes happen!”

Initially, lawmakers had hoped to reach an agreement by the end of this week, but as with many things in Congress, that deadline has slipped. Despite this delay, those leading the talks — including Murphy and Sen. John Cornyn (R-TX) — remained bullish on a possible agreement.

“This is a town where it’s fashionable to be pessimistic, so for my colleagues to be optimistic suggests there’s really cause for optimism,” Sen. Todd Young (R-IN), the former head of the Republican Senatorial Campaign Committee, told Vox.

Any bipartisan deal — even an incremental one — would be significant given how enduring the logjam on gun control has been. While mass shootings have increased in the US in recent years, Congress has been unable to find any meaningful compromise on the issue for more than a decade. A deal would show the public that Congress can actually make progress on gun control, and, more importantly, any compromise could open the door to more ambitious policies down the line.

“Success often begets success,” Sen. Tim Kaine (D-VA) told Vox. “It’s been a long time since we’ve done something meaningful on guns, a very long time, so if we’re able to do something solid, I think that could create conditions like ‘Hmm, Congress can act on guns.’”

What’s on the table

There are four main areas that the talks have focused on so far, according to a congressional aide. As Cornyn has repeatedly explained, whatever policy that emerges is likely to be “incremental” in nature, though it would still be the most progress lawmakers have made on guns in years.

Below are the four issues that lawmakers are currently discussing:

1. Red flag laws: A major component of any agreement is likely to be grants that incentivize states to either pass red flag laws or improve their implementation of them — an effort that builds on past negotiations between Sens. Richard Blumenthal (D-CT) and Lindsey Graham (R-SC). Currently, 19 states and Washington, DC, already have red flag laws, also known as extreme risk protection orders, which enable law enforcement to bar an individual from possessing firearms if they pose a risk to themselves or others.

Whatever bill the Senate passes would be aimed at encouraging more states to pass these laws, and at helping states with existing ones impose them more effectively. As was evident in a recent mass shooting in Buffalo, the efficacy of a red flag law is highly dependent on implementation, as well as on law enforcement and the broader public being aware of how to properly utilize them.

2. Enhancements to background checks: At this point, legislation that would impose universal background checks, much like the bill introduced by Sens. Joe Manchin and Pat Toomey in 2012, is not in contention due to Republican opposition. Instead, lawmakers are trying to see if more information can be required as part of background checks for 18- to 21-year-olds.

For example, in the case of an 18-year-old attempting to buy a gun, senators are looking at whether additional information from their juvenile records, which are presently left out, could be included as part of a background check.

3. Mental health resources: There’s also talk about increasing funding for mental health programs, which could include measures that help states bolster their efforts. One bipartisan bill previously introduced by Sens. Roy Blunt (R-MO) and Debbie Stabenow (D-MI) could be a model — it would fund behavioral health clinics that help provide mental health and addiction services.

4. School safety: And finally, there are discussions about policies to improve school safety and security, though lawmakers declined to share additional details about what this could include. Previously, Sen. Ted Cruz (R-TX) has introduced legislation that would allow schools to use grant money for campus design and stronger security measures.

Why it still matters even though it’s incremental

Anything the Senate passes is likely to be far less ambitious than what Democrats had hoped for and what experts say is needed to more significantly curb gun violence.

Earlier this week, the House passed a sweeping package of proposals including a ban on high-capacity magazines, a bill to raise the age limit for buying semiautomatic weapons from 18 to 21, and legislation that would require safer storage of guns in homes with minors. Policies like these could reduce gun violence by making it tougher to fire many rounds of ammunition at one time, and making it harder for younger people to obtain guns.

The House bills are widely expected to get blocked in the Senate, where any deal is poised to be quite limited.

Still, negotiators say it’s important to get something done in order to begin addressing public demands for more gun control, and show that it’s possible for Congress to make inroads on the issue. “We can help to build the muscle that we will use again by starting now,” Blumenthal told Vox.

Murphy has said, too, that this could be an opportunity to demonstrate to Republican lawmakers that any backlash they may face for supporting gun control would actually be far less than what many fear. Because of how vocal a minority of Republican voters have been on the issue, many GOP lawmakers have been reluctant to take any action on gun control due to concerns about the electoral blowback and potential primary challenges they could face.

As of now, there still isn’t a concrete agreement, but lawmakers were broadly hopeful going into the weekend on Thursday. Whatever emerges from these talks, they hope, will be a step forward in the wake of devastating recent tragedies.

“Everybody wants to get this done this work period,” Murphy told reporters, noting that senators aimed to finalize a deal before leaving for their next recess.