Only three students were shot at an American school Tuesday. Two of them were hospitalized, and only the 17-year-old gunman died. This made the attack at a southern Maryland high school a fleeting news item. The Austin, Texas, bombings edged it out.

The 1999 massacre at Columbine High School in Colorado opened a new horrifying chapter in U.S. gun violence. The nation stood transfixed for months. But a subsequent parade of mass shootings has worn down the shock over carnage on school property.

The public became so numbed that even the 2012 slaughter of 20 elementary school children in Newtown, Connecticut, failed to produce meaningful response in Washington. Many who have declared the quest for stricter gun laws hopeless may have been at this too long. You students haven’t.

The recent outrage in Parkland, Florida, reinvigorated the issue. Students and parents there are affluent and articulate and also possess a healthy sense of entitlement. They are not docile, and no, they are not going away. They are determined to keep their horror front and center as they campaign for tighter gun laws.

And they know whom to go after — not the National Rifle Association but the politicians the NRA controls. It was impressive how quickly Florida lawmakers wiggled out from under the NRA’s thumb when angry voters descended on Tallahassee. The state immediately toughened some of its lax gun laws, changes the NRA is now trying to block.

What is the NRA? For all its toxic fumes about evil government, the NRA is, at bottom, a lobbying group. Its mission is to help gun manufacturers make money. If that means putting weapons of war into the hands of unbalanced 18-year-olds, so be it.

I’m not going to bother with the NRA drone that “people kill people” and “you don’t know much about guns.” (The latter may be true, but military experts stand ready and eager to tell us what doesn’t belong in civilian hands.)

After meeting with grieving Parkland parents, President Trump briefly supported some sensible gun control measures, among them raising the minimum age for buying an assault rifle to 21. Pushback made him retreat and offer some largely cosmetic changes. None would prevent a 19-year-old, the age of the suspect, from getting his hands on an AR-15 assault weapon and killing many people almost instantly.

I am convinced that Trump genuinely wanted more meaningful action. Many of the white middle-class Parkland parents bear New York metro roots. They talked his talk. Trump simply lacked the guts to follow through.

Hurrah for the kids and adults who’ve revived a national movement for rational gun laws. This weekend’s March for Our Lives demonstrations could draw a million people.

You are doing the right things. You are smart to put a bipartisan frame around the issue and to emphasize the school safety aspect.

Know that you are winning. Major retailers have already dropped the sale of military-style rifles, especially to people under 21 — perhaps as acts of civic decency, perhaps to avoid disgusting other customers.

The more fearful you make the gun lobbyists the more they’re going to attack and mock you. But you know what? When it comes to command of social media, they have nothing on you.

So don’t let the short attention span of the news cycle slow you down. As Alex Wind, a Parkland high school junior put it, “we’re sick and tired of having to live with this normalcy of turning on the news and watching a mass shooting.”

The truth is that lawmakers who fear the NRA fear the voters even more. Something is telling them that the minute you are old enough to vote, you will.

Froma Harrop is a syndicated columnist. Follow her on Twitter @FromaHarrop. She can be reached by email at: fharrop@gmail.com.

Froma Harrop