In back-to-back votes, the House will take up two separate background check measures. On Wednesday it will consider the Bipartisan Background Checks Act, which would require background checks for all firearm sales, including those sold at gun shows and online. On Thursday it will turn to the Enhanced Background Checks Act, which would extend the time allotted for the F.B.I. to conduct background checks.
The action in the House reflects dramatic changes in the political climate over guns that culminated with last year’s midterm elections. A string of mass shootings, coupled with student-led activism after last year’s massacre at Marjory Stoneman Douglas High School in Parkland, Fla., produced a wave of Democratic candidates — including some from Republican-leaning districts — who ran and won while calling for limits on access to guns.
“It’s a real moment for the nation,” said one of those Democrats, Representative Lucy McBath of Georgia, who began advocating for gun control after her 17-year-old son, Jordan Davis, was shot dead in 2012. “We’re at a critical mass now where families are just saying they’ve had enough.”
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Democrats were punished roundly at the polls that year, with Republicans taking control of Congress and not relinquishing it for 12 years. For years afterward, Democrats were skittish about taking up gun-related bills.
The assault weapons ban expired in 2004, when Congress was under Republican control. When Democrats held the House from 2007 to 2011, no gun legislation was passed.
“There are still differences within our party as to how far we want to go,” Representative Steny D. Hoyer of Maryland, the House Democratic leader, told reporters on Tuesday. But Mr. Hoyer said he is convinced that the two bills being voted on this week have the support of the “overwhelming majority of the American people.”
Robin Lloyd, the managing director of the Giffords Law Center to Prevent Gun Violence, praised House Democrats for prioritizing the measures, noting that just a year ago, the Republican-controlled House tried — but failed — to pass legislation that would have required states to recognize concealed weapons permits issued in other states, effectively creating a national law allowing concealed weapons. That bill is a high priority for the National Rifle Association.
“Now we’re having the opposite conversation, and I do think that demonstrates how quickly this shift has happened,” Ms. Lloyd said. “It is a paradigm shift from where we were even 18 months ago.”
recent analysis by the Giffords Law Center.
That system has given rise to the so-called Charleston loophole, which allowed Dylann Roof, the white supremacist who killed nine people at a historically black church in Charleston, South Carolina, in 2015, to purchase a .45-caliber handgun even though he had previously admitted to drug possession, which should have barred him from obtaining the weapon. The enhanced background checks bill, sponsored by Representative Jim Clyburn of South Carolina, the majority whip, would give the F.B.I. 10 days to complete its determination.
“You’ve got a gun safety majority that is there because of the advocacy and the leadership of the young people from Stoneman Douglas who energized their peers both in Florida and around the country,” said Representative Ted Deutsch, Democrat of Florida, who represents Parkland. “They have helped deliver the gun safety majority in the House. That’s the importance of this moment.”