WASHINGTON – The House on Wednesday will hold its first major vote on gun control legislation in years, bringing to the floor two bills aimed at strengthening the background check system for gun purchases.

The changes would be the biggest expansion of the system since background checks were first required 25 years ago.

But while the Democratic-led House is expected to pass the bills, they’re unlikely to be considered in the GOP-controlled Senate.

Still, Democrats made the legislation an early priority in part because repeated mass shootings increased advocacy around the issue. That energy and activism helped Democrats retake the House.

Here’s what you need to know about the legislation.

What would the bills do?

One bill, H.R. 8, would require background checks for private transactions, such as purchases online and at gun shows. Currently, only federally licensed firearms dealers, importers and manufacturers are required to conduct background checks on customers under federal law. (Twenty states and D.C. have already expanded background checks to include at least some private sales.)

The other bill, H.R. 1112, would extend to at least 10 days the amount of time firearms dealers must wait for a response from the background check system before the sale can proceed. Currently, they can make the sale if they haven’t received a response in three days.

What are the arguments in favor?

Advocates say the bills would close loopholes in the background check system. For example, the gunman who killed nine people at the Emanuel African Methodist Episcopal Church in Charleston, S.C., in 2015, had a record that, under the law, would have made him ineligible to buy a gun, according to PolitiFact. But because of clerical errors in the FBI’s database, the background check was still going on after the three-day deadlin so the dealer was able to proceed with the sale.

About one in five gun owners surveyed in 2015 by researchers from Northeastern and Harvard universities said they obtained their guns without a background check – whether as a gift or through a purchase.

Would there still be exceptions?

Yes. Family members could still give guns to other close family members without conducting a background check, unless the relative is not legally eligible to own a gun. A gun could be loaned to another person while hunting or on a shooting range, so long as there’s no reason to believe the gun would be used to commit a crime and the borrower is legally allowed to have a gun. Other exceptions include a temporary transfer necessary to prevent “imminent death or great bodily harm.”

What are the arguments against?

Opponents say background checks are worthless unless they are paired with a national gun registry, and that would intrude on gun owners’ rights. They argue the changes would not have prevented some of the recent mass shootings, such as the 2018 mass shooting in Parkland, Fla., where the defendant had passed a background check. And they say the cost – up to $125 in some places – and extra hurdle of getting a background check could be a significant obstacle for those trying to defend themselves.

What do shooting survivors think?

The bill expanding background checks, H.R. 8, was introduced on Jan. 8, the eight-year anniversary of the mass shooting in Arizona that left six dead and that severely wounded Rep. Gabby Giffords and 12 others. Giffords, who co–founded a gun–control group after leaving Congress, is lobbying for the legislation on Capitol Hill this week.

But Louisiana Rep. Steve Scalise, another shooting survivor, opposes the legislation. The No. 2 House Republican said the bill would not have stopped his gunman, who targeted a congressional baseball practice in 2017. The bill would, however, take away the rights of gun owners, he said.

How much support does it have?

The bills passed out of the House Judiciary Committee this month on party-line votes. The House votes are expected to be similar, with just a handful of Republicans likely to vote for the legislation and a handful of Democrats expected to oppose the bills.

The Senate version of the background check expansion bill has no Republican cosponsors and Senate Majority Leader Mitch McConnell, R–Ky., is not expected to call it up for a vote. A similar measure didn’t survive a bipartisan filibuster when Democrats ran the Senate in 2013.

Why now?

Democratic leaders made the legislation an early priority, saying it was a top concern of voters in the 2018 elections. Gun control groups spent millions backing favored candidates, including Democratic Rep. Lucy McBath, the mother of a son killed in a shooting who was elected to an historically Republican district in Georgia.

In what the nonpartisan Center for Responsive Politics dubbed one of the biggest surprises of the midterm elections, gun control groups outspent pro-gun groups. That was mostly because of a big drop in spending by the National Rifle Association and its affiliates.

Besides demonstrating quick action, the early timing of the vote has another significance: Thursday is the 25th anniversary of the day the Brady Act, which mandated federal background checks, went into effect.

How many sales are denied?

Of the nearly 197 million firearms-related background checks conducted from when the law went into effect through 2015, about 3 million – or 1.5 percent – resulted in denials, according to the Bureau of Justice Statistics.

Does the bill have support?

An October survey by the Pew Research Center found 91 percent of Democrats and 79 percent of Republicans favored making private gun sales and sales at gun shows subject to background checks.

Contributing: Eliza Collins.

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