North Carolina voters will be asked this fall to remove a troubling ambiguity in the state constitution. An overwhelming, bipartisan majority of state legislators — 40 of 50 senators, 104 of 120 representatives — voted to place the amendment on the ballot.

Nevertheless, say some left-leaning critics, the measure is at best an unnecessary distraction — and at worst a conspiracy to get conservative North Carolinians to the polls.

It is neither. Voters should, and almost certainly will, ignore these objections and approve the amendment, which clarifies that “only a citizen of the United States who is 18 years of age and otherwise possessing the qualifications for voting shall be entitled to vote at any election in this State.”

Resident aliens are not currently allowed to vote in North Carolina, that’s true. And minors can vote in primaries only if they turn 18 by the date of the general election. But other jurisdictions allow noncitizens or minors to vote in local elections. And many activists explicitly advocate extending the franchise further.

We can’t know what future lawmakers or even judges may attempt. Here’s what we do know: only adult citizens should be able to participate in elections. Drawing bright lines here is essential to preserving what it means to be a citizen of a republic.

Here’s what the North Carolina Constitution currently states, Article VI, Section 1: “Every person born in the United States and every person who has been naturalized, 18 years of age, and possessing the qualifications set out in this Article, shall be entitled to vote at any election by the people of the State, except as herein otherwise provided.”

At first glance, that language may sound sufficient. It is not, however, as my John Locke Foundation colleague Andy Jackson argued in a recent paper.

The current provision (properly) requires equal treatment. If you are an adult citizen who is not currently serving out a sentence for a felony — that’s what the “except as herein otherwise provided” clause is about — you are guaranteed the right to vote. You can’t be excluded on the basis of race, ethnicity, religion, or other extraneous criteria.

Look more closely at the language, however. It states that every natural-born or naturalized citizen shall be entitled to vote, but it is “is silent on whether noncitizens can vote,” Jackson pointed out. “That silence can be exploited by legislators or judges into allowing noncitizen voting.”

There’s another problem with the current provision: it specifies only natural-born and naturalized citizens. That leaves out a small but equally worthy class of citizens. If you are born overseas but your parents are American citizens, you are, generally speaking, a citizen yourself. As Jackson observed, the ranks of such foreign-born citizens include US Sen. Tammy Duckworth (born in Thailand), US Sen. Ted Cruz (born in Canada), and Raleigh Dreamville music festival organizer J. Cole (born in Germany).

No one has tried to exclude such citizens from voting in the past, but why should North Carolinians cross their fingers and ignore the ambiguity? The proposed constitutional amendment would eliminate it. Rather than focusing only on who “shall be entitled to vote” — which doesn’t truly preclude additional grants of voting rights — the new language specifies that “only” adult citizens, regardless of how they became citizens, shall be entitled to vote.

We live in highly polarized times, to be sure. Trust, confidence, and mutual respect are diminishing. Too often, we assume that the ranks of the “other side” are populated by liars, ignoramuses, or villains rather than accepting the possibility of honest disagreement among people of good faith.

In that spirit, let me stipulate that I don’t think all critics of the citizen-voting amendment are secretly plotting to extend the franchise to noncitizens or minors. Some surely find the “belt and suspenders” argument I’m advancing here unpersuasive. They think revising the constitution’s ambiguous language is a waste of time.

They are mistaken. An important principle is at stake. Let’s button those suspenders securely.

John Hood is a John Locke Foundation board member. His latest books, Mountain Folk and Forest Folk, combine epic fantasy with early American history.