Susan Walsh/AP
Opinion writer

With the ascension of Brett M. Kavanaugh to the Supreme Court, we are finally having an active discussion about the causes and consequences of minority rule, the fact that we are now in a situation where the Republican Party controls all the critical institutions of power in Washington (and most in the states) despite having the support of a minority of the public.

We just saw a president elected by a minority of voters appoint a highly ideological justice who was confirmed by senators elected by a minority of voters, and who will now enact a legal revolution most Americans will oppose. It is also entirely possible that most Americans will vote for Democrats for the House this November only to find that Republicans manage to hold on to control of Congress.

While we often concentrate on abortion when discussing how Kavanaugh will shift the court, there is another key area of law we need to pay attention to. Not only will the newly conservative majority give Republicans ideological victories, they are also almost certain to make one ruling after another that enables Republicans to solidify and enhance minority rule by suppressing the votes of Americans who are likely to vote for Democrats.

We have now gotten a taste of what is to come in a ruling that didn’t involve Kavanaugh but shows where this is all going. The court declined to hear an emergency appeal in which voters in North Dakota challenged a law that not only requires voters to show ID at the polls, but also requires those IDs to have street addresses, not P.O. boxes. The fact that the court didn’t rule on the case probably means the judges were split 4-4, so an appeals court ruling upholding the law will stand.

What’s the big deal, you might ask — shouldn’t IDs have street addresses? But if you understand North Dakota, you know that this law was specifically aimed at disenfranchising Native American voters, who vote heavily for Democrats.

In North Dakota, many of those voters live on reservations, which are often remote and spread over vast areas. So it is common for people’s homes to be on roads with no official name, leaving them without an official address and with no postal delivery. They get their mail from a P.O. box at the nearest post office.

Let’s be clear about this: North Dakota Republicans are absolutely aware of this fact. It’s not like they were shocked to learn that many Native Americans who live on reservations in their state don’t have street addresses. That was the whole point. This law was passed with one intent and one intent only: to make it harder for Native Americans to vote and to reduce the numbers who successfully make it to the polls.

Not only that, the new rule also wasn’t in place for the primary election but will be sprung on voters in the general election, many of whom will show up to their polling place only to find that they’ve been barred from voting.

It just so happens that there is a hotly contested Senate race in North Dakota this year, in which incumbent Democrat Heidi Heitkamp has been trailing in the polls. It is entirely possible that control of the Senate could hinge on the success of this Republican voter-suppression effort.

Six years ago, Heitkamp won her race by only 3,000 votes, in a state where the entire turnout in that presidential year was just over 300,000. As Ruth Bader Ginsburg pointed out in her dissent to the ruling:

(1) 70,000 North Dakota residents — almost 20% of the turnout in a regular quadrennial election — lack a qualifying ID; and (2) approximately 18,000 North Dakota residents also lack supplemental documentation sufficient to permit them to vote without a qualifying ID.

In a state as small as North Dakota, a little voter suppression can go a long way.

Had Kavanaugh been on the court when this case was heard, he almost certainly would have turned that 4-4 split into a 5-4 ruling that could be cited as precedent by other states looking for creative ways to disenfranchise minority voters.

Hold on, you may be saying. Is Kavanaugh really going to be much of a change from his predecessor Anthony M. Kennedy, who was not exactly a friend to voting rights? After all, among other things, Kennedy signed on when the court’s conservatives eviscerated the Voting Rights Act in 2013 and recently validated Ohio’s voter purge that disenfranchised large numbers of African Americans.

But Kennedy at least showed the occasional flash of sympathy for the principle that voting in America should be governed by something other than the raw power of whichever party happens to be in charge. Earlier this year, the court declined to rule on a case challenging partisan gerrymandering. But Kennedy seemed sympathetic to the idea that partisan gerrymanders could be unconstitutional but was unsure whether the court could establish a workable standard. Kennedy also joined with liberals in 2015 to uphold an Arizona ballot measure in which voters gave the power to draw district lines to an independent commission instead of to the GOP-controlled legislature; the four other conservatives were vehemently opposed.

With Kavanaugh on the court, there will be none of that. Kavanaugh is not just a conservative ideologue but also a longtime Republican Party activist. When it comes to voting rights, he is almost certain to do what is good for the GOP and what the GOP wants.

That means that not only will Kavanaugh and the other conservatives probably reinforce previous rulings doing things such as upholding voter ID laws that disproportionately affect minorities. They’re also going to push the envelope even further. Every Republican legislature now knows that it can go as far as it wants to suppress votes — and the Supreme Court is almost certain to approve it.

We are likely to see a wave of cases in which Republican state legislatures have passed laws that 1) plainly suppress the votes of those who are more likely to vote Democratic, especially racial minorities; and 2) are plainly designed with that intent. All they will need to justify the voter suppression is some claim of innocent intention, no matter how dubious or disingenuously offered.

This issue got almost no attention during the controversy over Kavanaugh’s nomination. But make no mistake: It’s one of the main reasons Republicans are so giddy with joy now that he is on the Supreme Court. It’s a lot easier to keep winning elections when you can rig the game in your favor.