The gun debate in America will soon enter a new chapter with a Democrat in the White House after four years under President Donald Trump in which gun control advocates developed a long wish list for reform amid a spate of large-scale mass killings in places like Las Vegas, El Paso and Parkland, Florida.

But any hope that Joe Biden will usher in a new era of restrictions on firearms is highly unlikely because of the same polarization in Washington that has tripped up similar efforts under past administrations.

The items on the agenda — largely relegated to the political shelf in recent years — include renewing a ban on AR-style rifles, universal background checks, restrictions on high-capacity magazines and a federal red flag law designed to prevent people at risk of harming themselves or others from purchasing a firearm.

But virtually all of those will require Congress to act. And regardless the outcome in two Senate races in Georgia that will determine which party holds the majority in that chamber, it will be a tall order to get a majority of lawmakers on board.

One key reason is because the issues have become so polarized. Years ago, gun politics crossed party lines, and it was easier for Republicans and Democrats to find common ground.

“It used to be a cross-cutting issue, there used to be Democrats that were very pro-gun and Democratic legislators who won districts in part on their pro-gun views,” said Matt Grossmann, an associate professor at Michigan State University and director of its Institute for Public Policy and Social Research who follows gun politics. “And you just don’t have that anymore.”

The number of firearms in circulation has mushroomed in the past 12 years, starting in President Barack Obama’s administration when gun owners feared he would push through significant restrictions.

It continued unabated during Trump’s lone term. In the first years of his tenure, Americans amassed firearms amid fears about new gun measures following mass killings. The gun buying picked up even more steam in the past year as civil unrest, economic turmoil and the pandemic propelled unparalleled buying sprees.

And with the pandemic dominating the conversation, guns took a back seat in the 2020 election.

Gun control groups still want to be heard, however. For one, they want universal background checks that would require the review for virtually every sale of a firearm, and a ban on online sales of firearms, ammunition and parts.

Among the legislative proposals, the one viewed as having some bipartisan support is a federal “red flag” law that would make it easier to temporarily confiscate firearms from someone deemed a risk to themselves or others. Currently, fewer than two dozen states have such laws on the books.

Gun control groups also are more aggressively underscoring the fears they have about the abundance of guns in homes of Americans. They worry about the toll it will have on households where firearms are present, both through murder-suicides and suicides.

During a news conference Thursday announcing their priorities for Biden to take executive action on guns, Everytown for Gun Safety cited statistics that show calls into domestic violence hotlines and suicide hotlines up, and gun violence in cities on the rise. Their list of priorities includes restricting access to untraceable “ghost guns” and cracking down on people who are able to purchase a firearm if the FBI background check isn’t conducted within the required 3 business days.

“The need for action is urgent,” said Michael-Sean Spence, Everytown’s director of community safety initiatives. “This was already a public health crisis before COVID arrived — and the pandemic has made things far worse.”

There are other steps Biden can take administratively. Among the key items likely to be pursued is a rule enacted in the waning weeks of the Obama administration but scrapped by Trump soon after taking office: requiring the Social Security Administration to provide information to the gun-buying background check system on recipients with a mental disorder so severe they cannot work or handle their own benefit checks. The rule would affect an estimated 75,000 beneficiaries.

The most coveted piece of legislation by gun control advocates has been a renewal of the ban on “assault weapons” that expired in 2004. Biden played a central role in pushing through that decade-long ban, and he has pledged to push for another ban on the semiautomatic long guns that have only surged in popularity since their return to the market.

Much has changed since that ban was pushed through — from the political landscape to the saturation of those firearms in the civilian market.

In the years leading up to and following the ban, there were an estimated 8.5 million AR-platform rifles in circulation in the United States. Since the ban was lifted, the rifles — called “modern sporting rifles” by the industry — have only surged in popularity. The National Shooting Sports Foundation now estimates there are more than 17 million in circulation. And there are likely significantly more after this year, which consistently smashed monthly records for federal background checks.

The National Rifle Association, which poured tens of millions of dollars toward electing Trump in 2016, has been weakened by infighting as well as legal tangles over its finances. While it remains a force in the gun arena, it’s unclear what influence it will be able to muster during the Biden administration.

Alan Gottlieb, the founder of the Second Amendment Foundation, said he’s watching for the outcome of two runoff elections in Georgia that will determine which party controls the U.S. Senate. But regardless what happens, he’s hopeful that efforts to severely restrict firearms will face resistance in the courts after four years of Trump appointing conservative justices throughout the federal court system as well as on the U.S. Supreme Court.

“We know where they’re coming from, we know what they want to do. They have a very long laundry list of things they’d like to accomplish,” Gottlieb said. “And we’ll see where we go with that.”