Once again, Congress faces the question of whether it will pass any substantive gun control measures to curb mass shootings, this time in the wake of three events in less than a week where gunmen opened fire on crowds in public settings, killing at least 34 people.

And once again, any effort to change the nation’s gun laws must shake free from years of stalled legislation, lately caused by Senate Majority Leader Mitch McConnell and Republican lawmakers, and potentially a conservative Supreme Court that could be poised to stop such measures.

[Trump opts against call for gun-control bill after Dayton and El Paso shootings]

President Donald Trump addressed the nation Monday and called for “real bipartisan solutions” to stop the attacks. The president mentioned legislation to allow courts to take firearms away from people suspected of being a danger to the public, a so-called “red flag” law backed by Senate Judiciary Committee Chairman Lindsey Graham, who is working on a bill with Sen. Richard Blumenthal.

But Trump stopped short of calling for gun control legislation. And he did not call for Senate votes on House-passed legislation to expand background checks to cover all firearm purchases and to lengthen some wait times under that background check system — despite his tweet earlier in the day that “Republicans and Democrats must come together and get strong background checks.”

House action

The expanded background check bill passed the House in February with the backing of Democrats and several Republicans, but McConnell shows no sign of allowing a vote on it. The Trump administration issued a veto threat because the “burdensome requirements in the bill do not sufficiently protect Second Amendment rights.”

The gun control issue clearly falls along partisan lines in Congress. From the perspective of Democrats — who almost exclusively propose legislation to address gun violence and in 2016 staged a historic Senate filibuster and a sit-in on the House floor over the proliferation of mass shootings — the call for bipartisan solutions falls flat when it comes to the Kentucky Republican who controls what gets a Senate vote.

“Mitch McConnell, stop being a coward and allow a vote on bipartisan bills the House has already passed to help prevent gun violence,” tweeted Rep. Mike Thompson, who introduced the expanded background check bill.

Those efforts are popular. The Pew Research Center found in October that 91 percent of Democrats and 79 percent of Republicans favor background checks for private gun sales and sales at gun shows.

Republicans, however, say the bills would only criminalize gun transfers between law-abiding citizens and burden them when buying or trading guns, and would not solve the gun violence problems it seeks to address. They also say enforcing the bill would take a federal registry, which they oppose.

Congress took limited action in 2018 after the deaths of 17 people at a Parkland, Fla., high school. Lawmakers provided $1 billion over 10 years in federal grant funding for school design and teacher training to bolster student safety — the only federal law to address mass shootings at schools.

[The House passed 2 gun control bills, but Democrats aren’t in a rush to do more]

Lawmakers also strengthened compliance with the current background check system for firearm purchases. And the Trump administration banned bump stocks after a mass shooting in Las Vegas in October 2017 where the attacker used one to more rapidly fire a rifle.

Democrats have been clamoring for more.

Speaker Nancy Pelosi, during a Democratic Caucus conference call Monday, said that as two new mass shootings took place this weekend, she talked with families of previous gun violence who want to put pressure on McConnell to bring up the House-passed bill to expand background checks for gun purchases.

“They’re not into politics. They’re into policy and that’s exactly where they should be,” Pelosi said, according to a Democratic aide on the call. “And they urge us to help — to give us guidance on how we go forward.”

Graham said Monday that he reached an agreement with Blumenthal and will introduce legislation “very soon” to create a federal grant program to encourage states to adopt the “red flag” laws that intervene with those deemed dangerous.

While there was no clear indication that background check measures would have prevented the three mass shootings in California, Texas and Ohio, there was also no clear sign that a red flag law would have either.

“May not have mattered here, but Red Flag laws have proven to be effective in states that have them,” Graham tweeted Saturday after the El Paso attack.

Assault weapons ban

House Democrats, in the Commerce-Justice-Science portion of a massive spending bill passed in June, eliminated four firearm provisions that had been in the measure for years.

But such proposals are modest compared to others that face even stronger political headwinds, such as measures to ban certain weapons that have no Republican co-sponsors.

“Banning assault weapons and high-capacity magazines, tightening background checks, closing loopholes and giving states the ability take guns away from dangerous people are all proposals supported by overwhelming numbers of Americans, but Republicans in the Senate refuse to take up these bills,” said California Democrat Dianne Feinstein, who introduced the Senate version.

Instead, Trump on Monday urged efforts to curb violent video games — despite a lack of evidence that they contributed to the mass shootings — as well as efforts to address mental health. He said he directed the Justice Department to propose legislation that people who commit hate crimes and domestic terrorism quickly face the death penalty “without years of delay.”

He also directed the FBI and DOJ to divert resources for greater law enforcement spending to combat hate crimes and domestic terrorism. That possibility could enter the conversation in September as Congress works to fund the government after the end of the fiscal year Sept. 30.

FBI Director Christopher Wray told the Senate Judiciary Committee on July 23 that domestic terrorism was a “steady threat” and said that some version of white supremacist violence played a role in many of the investigations.

“Trends may shift, but the underlying drivers for domestic violent extremism — such as perceptions of government or law enforcement overreach, socio-political conditions, racism, anti-Semitism, Islamophobia, and reactions to legislative actions — remain constant,” Wray put in his written statement to the committee. “The FBI is most concerned about lone offender attacks, primarily shootings, as they have served as the dominant lethal mode for domestic violent extremist attacks.”

Less than two weeks later, a gunman killed at least three at a festival in California, 22 at a Walmart in El Paso, Texas, and nine in an entertainment district in Dayton, Ohio.

The cluster of shootings, along with a manifesto apparently left behind by the El Paso shooter that identified a racial motive for the attack, sparked anew the discussion of federal legislation.

Judicial hurdle

Even if stronger laws passed, there’s some question about whether they would pass Supreme Court review.

The Supreme Court has never weighed in on the constitutionality of the first assault weapons ban that Congress allowed to expire, and the justices for the past nine years have avoided major cases that address the extent to which Congress or state lawmakers can pass laws that restrict firearms.

But the conservative wing of the Supreme Court, bolstered by Trump’s picks of Justices Neil M. Gorsuch and Brett M. Kavanaugh, could press the high court to jump back into the incendiary national debate over gun control laws.

The court agreed to hear a Second Amendment case about a New York City law that limits transportation of firearms, but the city and state — perhaps fearing a loss in the case — changed those laws and suggested that the case is moot and should not be decided.

Lindsey McPherson contributed to this report.