When politicians campaign for office, they usually portray themselves as potent and powerful, even when they aren't. Elect me, they say, and everything will be transformed, no matter how absurd it is to think that some backbench freshman member of Congress is going to "change the way they do business in Washington" or "get our economy back on track."

There is one area, however, where politicians (especially those from one party) work hard to tamp down expectations and say that there's really nothing they can do about one of the country's most pressing problems: guns.

The party, of course, is the Republicans. And after yet another massacre inside a school committed with a military-style rifle, they want to make sure everyone understands that passing laws — the thing they are elected to do — is pointless, so there's really no point in trying.

The blood hasn't even been cleaned off the floor before you can find prominent Republicans saying that gun violence is like the weather. You might want to prepare for it — give your kids active shooter drills, like you'd put an umbrella in your bag if you think it might rain — but it certainly can't be stopped. As Marco Rubio said on Thursday, the day after 17 of his constituents were slaughtered in Parkland, "I'm trying to be clear and honest here, if someone's decided to commit this crime, they'll find a way to get the gun to do it." His colleague Ted Cruz told Fox & Friends, "We have seen that evil can occur whether at Parkland or at a church in Central Texas, or in schools across the country. There are murderers. Evil is, sadly, always present." What are you gonna do?

Imagine what the response would be if after a terrorist attack, a senator said, "There's no point in beefing up security at airports. If someone has decided to commit an act of terrorism, they'll find a way to do it. Evil is, sadly, always present."

That's not how we react to terrorism. We don't treat it as inevitable, we try to figure out how to stop it. And in fact, our representatives made a choice after 9/11 to take all kinds of measures that infringed on civil liberties and were of questionable practical value in order to forestall future terrorist attacks.

It takes about a month for as many Americans to die from gunfire as perished in the 9/11 attacks, yet we make a choice to do nothing.

In addition to their protestations of the futility of any action to address gun violence, Republicans have a second response, offered with almost perfect bad faith: The real problem isn't guns at all, they say, but mental illness. But what do they propose to do about our mental health system? Well ... nothing. That's not to mention the fact that mental illness doesn't actually have much of anything to do with gun violence.

But even if it did, here's something you might not have realized: In other countries, the ones where gun violence is a fraction of what it is in the United States? They have mental illness too! They also have domestic abusers (there's a strong connection between mass shooting and domestic violence), and angry young men. What they don't have is gun laws as permissive as ours.

Those laws, the ones that make it easy for someone like Nikolas Cruz to get an AR-15 so easily when he isn't even old enough to buy beer, were also a choice that we made. There was nothing futile about it. They express the values of the people who advocated for them, and they have profound and powerful effects on the society we've constructed.

For their part, Democrats have their own narrative of futility, but it's one that unfortunately too many of them actually believe. It says that there's no point in trying to change gun laws, because the NRA has a stranglehold on Congress and they'll only risk their jobs if they try.

While it's true that the GOP has wedded itself to the extremist ideology of gun rights advocates, there's nothing futile about opposing the NRA. People do it all the time. Barack Obama did it, and he got elected twice. Last year in Virginia — the state where the NRA is headquartered — the group's favored candidates got wiped out, despite the fact that they poured millions into the election. They fought against the Democratic candidates for governor, lieutenant governor, and attorney general, all of whom won. "Each one of us is very proud of our F" rating from the NRA, said the now-lieutenant governor, Justin Fairfax. There were 13 competitive state house races where the NRA endorsed a Republican and gun safety groups endorsed the Democrat — and Democrats won 12. The 13th was the race that was tied and had to be decided by drawing lots.

You might protest that this was an election where Democrats did well up and down the ballot, and you'd be right. But that's just the point: The NRA can't destroy its enemies when Democratic voters are motivated and energized.

Which brings us to the most important lesson Democrats need to learn: A belief in the futility of action inevitably becomes a self-fulfilling prophecy. If you accept that there's no point in trying to pass measures to reduce gun violence, nothing happens and the pro-gun side only gets stronger. If you're too afraid to argue for those policy changes, the public never hears the arguments and won't be motivated to support you. If you resign yourself to the pro-gun voters being more engaged on the issue and so you never try to get those who agree with you engaged, the engagement gap will only widen.

Even if gun violence can never be reduced to zero, we can pass gun safety laws that would actually reduce the unending carnage so many people would have us accept as an inevitable feature of American life. We just have to be willing to try.