I’m a libertarian, which means I believe in limited government. Laws restrict liberty, and libertarians tend to prefer fewer laws to more laws. I’m also a professor of constitutional law, which means I teach about US Supreme Court opinions for a living. Finally, and perhaps most important, I’m not an ideologue. Only an ideologue would think that the Second Amendment to the US Constitution prohibits reasonable gun regulations.

Tuesday’s horrific mass shooting at an elementary school in Uvalde, Texas — the honey capital of the world — has reignited the gun-control debate in the United States. Nineteen children — beautiful, innocent — and two beloved teachers were murdered by an 18-year-old gunman who purchased two assault weapons for his 18th birthday and then bragged on Facebook about the murders he was about to commit.

In response to a reporter’s questions about potential support for strengthened background checks after the Uvalde shootings, the retiring Sen. Richard Shelby (R-Ala.) said, “I’m a Second Amendment person, period.” Shelby is rated A+ by the National Rifle Association.

Ted Cruz called for armed law enforcement on school campuses and faulted Democrats for politicizing the issue. Cruz is a Republican elected to represent the people of Texas in the US Senate. He is scheduled to speak at the May 27-30 NRA leadership summit in Houston, which has been in the works for months.

The NRA confirmed on Twitter Wednesday afternoon that the event would proceed. The organization said that while an investigation is “still underway,” officials “recognize that this was an act of a lone, deranged criminal.”

The NRA is, of course, one of the most powerful lobbying groups in America and one of the most aggressive opponents of gun regulation. As a result, support for gun rights is baked into the Republican Party’s platform.

I’m not a Democrat, and I didn’t vote for President Joe Biden. But the president was correct as a matter of constitutional law when he noted on Wednesday, “The Second Amendment is not absolute.”

Even the late Justice Antonin Scalia, who wrote the landmark 2008 DC v. Heller opinion that held the “right to keep and bear arms” is an individual right, appreciated that the Constitution does not prohibit reasonable gun regulations. In his opinion, Scalia made many statements acknowledging that regulation and restriction of, for example, modern military-style assault weapons are consistent with the original understanding of the Second Amendment.

“Like most rights, the right secured by the Second Amendment is not unlimited,” Scalia wrote. “The sorts of weapons protected were those ‘in common use at the time.’ We think that limitation is fairly supported by the historical tradition of prohibiting the carrying of ‘dangerous and unusual weapons.’ ”

Sens. Shelby and Cruz, as well as the NRA and other politicians who adopt the absolute no-regulation approach to gun rights, should reread Scalia’s Heller opinion. After all, Scalia was the most influential voice in the conservative legal movement, Heller was his most significant majority opinion for the nation’s highest court, and Heller and its core holding are here to stay.

Indeed, as Scalia also appreciated, no constitutional right is absolute. The First Amendment proclaims, “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.”

But only the idiosyncratic Justices Hugo L. Black and William O. Douglas insisted that “no law” meant “no law” where the First Amendment was concerned, and that was decades ago. A majority of the court has never taken that view. The Second Amendment, moreover, is devoid of the absolutist “no law” language that the NRA and its acolytes promote.

To end where I began, libertarians aren’t anarchists. Elected officials shouldn’t be sycophants for the NRA. As Uvalde’s most famous son, Oscar-winning actor Matthew McConaughey, aptly noted in a heartfelt Instagram post shortly after learning of this latest shooting massacre, “We cannot accept these tragic realities.”

The Constitution says we don’t have to accept them. Can we start by enacting laws that require universal background checks, ban assault weapons or, at a minimum, raise the legal age to 21 for purchasing assault weapons like Gov. Kathy Hochul suggests?

Scott Douglas Gerber is a law professor at Ohio Northern University and an associated scholar at Brown University’s Political Theory Project. His nine books include, most recently, “The Art of the Law.”