For days now, the airwaves and social media have been filled with the voices of young people, thick with righteousness and anger, vowing “never again.”

But will the student- led protests against gun violence dramatically change the politics and lead the president and Congress to act in a way that other explosions of fury and grief — after Virginia Tech, Aurora, Newtown, Charleston, San Bernardino, Orlando, Las Vegas — have not?

Maybe. Maybe not.

It will take time — not the next few days or weeks, but months and even years — to know whether last week’s slaughter of 17 people at Marjory Stoneman Douglas High School in Parkland, Fla., was a watershed or just another in the litany that has turned the ritual of tears, recrimination and political stasis into a familiar cycle.

Few issues are as charged as the debate over gun control and gun rights, resting as it does on the principles of life and liberty. At stake, for some, is freedom from fear. For others, it is freedom from an overweening government.

For many, it’s black or white, with no gray in between.

In 1994, the Democratic-run Congress approved and President Clinton signed into law the Violent Crime Control and Law Enforcement Act, the most sweeping anti-crime bill ever passed. It had many provisions, including money to hire 100,000 new police officers and $10 billion for prisons. Among the most controversial aspects was a ban on the possession, manufacture, use and importation of 19 types of semiautomatic firearms.

The ban was provisional, lasting 10 years unless Congress specifically authorized its extension, which it did not. With Republicans in control, the provision lapsed in September 2004. Democratic Sen. Dianne Feinstein of California, one of the authors of the original ban, has repeatedly tried without success to pass a new version.

There have been many, most of which died a quiet death. Some proposals, such as barring people on terrorist watch lists from buying guns, or extending background checks to firearms purchased online or at gun shows, passed the Senate but failed to clear the House. None has been enacted into law.

In 2005, the Republican-run Congress passed and President George W. Bush signed into law a measure protecting firearm manufacturers from being sued for crimes committed with weapons they produced.

And last year, President Trump signed a bill into law rolling back an Obama-era regulation that made it harder for people with mental illnesses to buy a gun.

Indeed. And it can be explained as simply as Democrats losing the House majority they held for 40 years, as well as control of the Senate for much of the last two decades.

Ah, yes. Polarization.

There used to be a decent-sized segment of the Democratic Party supportive of gun rights and lawmakers who reflected those views. But most of those legislators have died, retired or been replaced by Republicans, some of whom explicitly ran against the Democratic Party and policies like the ban on semiautomatic weapons. For most Democrats running for Congress, gun control is now unassailable orthodoxy.

The Republican Party, conversely, has grown even more staunchly pro-gun. The share of Republicans who said it was more important to protect the rights of gun owners than enact new gun controls rose from just under half in 2008, the last year of Bush’s presidency, to about 8 in 10 Republicans in 2016, according to a national Pew poll.

More recently, a Washington Post-ABC News poll conducted just after the Florida school shooting found a similar divide. Nearly 9 in 10 Democrats said stricter gun laws could have prevented the tragedy, compared with fewer than 3 in 10 Republicans.

While 71% of Democrats supported a ban on assault-style weapons, according to the survey, only 29% of Republicans were in favor. That compares to more than 7 in 10 Republicans who supported such a ban in a 1999 survey.

That is true.

Largely because of staunch opposition from the National Rifle Assn. and its allies, who fear impingement of the 2nd Amendment, which states “the right of the people to keep and bear Arms, shall not be infringed.” For most Republican House members, the greatest political threat they face on gun issues is a primary challenger accusing them of being insufficiently tough in protecting the rights of gun owners. So that tends to push lawmakers away from compromise.

Because intensity matters, and opponents of gun control have tended to be more passionate and stay much more engaged than supporters of restrictions. As Robert Spitzer, an academic expert on gun policy, explained after last summer’s armed assault on Republican lawmakers outside Washington: “It’s only when the mass shooting occurs that the public pays real attention. But the sentiment doesn’t last long. Most people turn their attention to other things, as does the media, and soon it’s back to business as usual.”

Perhaps. But it’s only been a little over a week since the Feb. 14 attack in South Florida. The test is still to come.

Who will have greater sway in November’s midterm election — supporters of gun control or activists who feel any type of crackdown tramples their constitutional rights? Will any incumbents be ousted because they are perceived as being too supportive of gun rights? That would be a significant change in the political dynamic.

Will Trump follow through on the promise he made to strongly push for comprehensive background checks, limiting the guns that can be purchased by someone under age 21 and ending the sale of “bump stocks” that enable a semiautomatic weapon to fire faster?

He also promised to solve the plight of so-called Dreamers — children brought to the United States illegally — but his stance has repeatedly shifted and they remain in limbo.

In short, action and not words will determine whether this time is really different.

mark.barabak @latimes.com

Twitter: @markzbarabak