Photo: AP

A filibuster led by Democratic senators demanding new gun control measures in the wake of this weekend’s deadly shooting in Orlando continued past the 13-hour mark Wednesday evening, making it one of the longest such actions in modern Senate history.

At 11:21 a.m., Connecticut Democrat Chris Murphy began speaking, vowing not to give up the Senate floor “until we get some signal, some sign that we can come together.” Dozens of senators, including one Republican and one Independent, joined Murphy’s effort throughout the day, which focused on two possible gun control amendments to a spending bill. From the Associated Press:

Murphy is seeking a vote on legislation from Feinstein that would let the government bar sales of guns and explosives to people it suspects of being terrorists. Feinstein offered the amendment in December, a day after an extremist couple killed 14 people in San Bernardino, California, but the Republican-run Senate rejected the proposal on a near party-line vote. Murphy also wants a vote to expand background checks.

The Orlando shooter, Omar Mateen, was added to a government watch list of individuals known or suspected of being involved in terrorist activities in 2013, when he was investigated for inflammatory statements to co-workers. But he was pulled from that database when that investigation was closed 10 months later.

Republicans have argued that the so-called “no fly, no buy” law denies due process rights to Americans erroneously placed on the secret, often inaccurate terrorist watch list. Wednesday evening, Republican Senator Pat Toomey said that lawmakers were still working toward a potential compromise.

“There are some discussions under way,” Toomey told The Wall Street Journal. “It’s a process that’s in the works.”