He called it a lesson in “How Republicans are born.”

Grover Norquist, the anti-tax crusader, was on Twitter Sunday, recounting how his 8-year-old “has been saving up to buy her first Guitar. Found it for $35. She had 35 exact. Then … sales tax.”

If he could, one suspects Norquist would have accompanied the last two words with scary music. Say, the shark theme from “Jaws” or the shower music from “Psycho.”

“Everybody run! It’s … it’s … the sales tax!”

The twitterverse was only too happy to point out the obvious to Norquist and his traumatized daughter. Namely, that the tax on her guitar — that princely $2 and change — helps pay for the road over which the guitar traveled to the store. And the police who defend the store from being robbed. And the firefighters who respond if it catches fire. And, in whole or in part, the school where Norquist’s daughter learned to count to 35 in the first place.

But at risk of piling on, there is another point that bears making here, a simple and obvious one that tends to get lost in the GOP’s loud acrimony toward this government surcharge. Namely, that we pay taxes as an investment in the common good. It’s a prosaic, unlovely little ritual which is nevertheless more patriotic — and more substantive — than fireworks on the Fourth of July.

That’s not to say it’s fun. Sacrifice seldom is. Nor is this an endorsement of wasteful government spending. To the degree Republicans or anybody else oppose that, no sensible person can disagree.

But as Norquist’s tweet suggests, the contention of many Republicans is not that over-taxing is bad, but that all taxing is bad. And that amounts to a retreat from the very idea of a common good. Exhibit A: the party’s latest proposal to overhaul health care, and the “Let ‘em eat cake responses” to the idea that 22 million people will be deprived of coverage in order to finance tax breaks for the very wealthy.

For example, Vice President Mike Pence touted this as a new system based on “personal responsibility.” He did not specify what failure of “personal responsibility” he finds in people with disabilities who won’t be able to get treatment under the Republican plan.

Kellyanne Conway opined that those who lose their Medicaid “can always get jobs.” Which will doubtless surprise many low-income workers who depend on it. They thought they already had jobs, albeit jobs that don’t offer health insurance.

A woman on Twitter asked what will happen to her son “born at 26 weeks with a serious heart condition.” Another woman replied: “Sorry about your son, but what would he have done 200 years ago things are much better but nothing is promised to anyone.”

There is something chilling about that dismissal, something deeply selfish and antithetical to a nation founded upon an ideal of individual human worth. One is reminded of a Springsteen song: “We Take Care of Our Own.”

But do we still believe that? Or are we now a nation where we only take care of ourselves?

“Sorry about your son?!”

That’s not good enough.

We pay taxes, fund libraries, schools, fire and police departments and, yes, health care, so that her son and all our sons and daughters have the best possible shot at the best possible life.

At some point, you have to grow up and realize that you are not in this world only to gratify yourself, that each of us has an obligation to all of us, and that this is where our goodness — and thus, our greatness — resides.

That’s how Americans are born.

Leonard Pitts is a columnist for The Miami Herald.