If you’re watching for waves in the current election, keep your eye out for a wave of voter suppression.

In Illinois, people already are voting at early-voting sites or via mail-in ballots. Unlike in the past, those who aren’t registered can sign up to vote right up until Election Day on Nov. 6. It’s a much more convenient — and democratic — system than the days when a long day at work, a blizzard or a family emergency could make it impossible to get to the polls.

EDITORIAL

But in some of our neighboring states and around the nation, efforts are afoot to discourage people from voting, violating the very idea of a government that rules based on popular will.

We all should be outraged at this assault on our democratic values, and we should insist other states encourage people to vote, not put up barriers.

According to the Brennan Center for Justice, at least 99 bills to make it harder to vote were introduced last year in 31 states. We see the results everywhere.

In North Dakota, with approval from the Supreme Court, voters need IDs showing their address. That leaves out many people on Native American reservations who use P.O. boxes. Because Native Americans make up 5 percent of the state’s voters, that could tip what is now a very close Senate race.

In Georgia, Secretary of State Brian Kemp, who is running for governor, is using an “exact-match law” to put 53,000 voter-registration applications on hold. Nearly 70 percent of the suspended applications are those of African-Americans, even though they make up only 32 percent of the state’s population.

Georgia also purged more than a half-million voters from the rolls last year, many of them under a rule that allows people to be purged if they haven’t voted recently.

Closer to home, Republican lawmakers in Indiana, Iowa, Wisconsin and Ohio, have passed strict voter-I.D. or roll-purge laws, which discourage turnout among groups that tend to vote Democratic.

For people who don’t have driver’s licenses, getting a getting a government ID to vote can mean traveling to state agencies that sometimes have very limited hours, taking a day off work and assembling personal documents. Aggressively purging voter rolls, often using the controversial and error-prone Interstate Voter Registration Crosscheck Program, can mean people who believe they still are registered will find out otherwise when they show up to vote.

Wisconsin has a photo ID law that some believe tipped the 2016 election in that state. Critics say an Iowa voter ID law that will be in partial effect in this election will disenfranchise many students. Ohio, like Georgia, has enacted a law that strikes people from the voting rolls if they haven’t voted recently.

RELATED

• EDITORIAL: Don’t let Illinois data be used for voter suppression

• EDITORIAL: Illinois should be protecting voters, not undercutting them

Voter suppression is just one tool that is upending elections. Outside interference through social media and dark money or uncapped campaign spending also takes a toll. But that’s all the more reason voter suppression should be relegated to history, along with poll taxes and literacy tests.

Over the past couple of months, the Sun-Times Editorial Board has interviewed candidates running in dozens of Chicago-area races. We’ve heard spirited discussions and a wide range of ideas.

Those ideas, not ballot-access trickery, are what should decide elections.

Send letters to letters@suntimes.com.