At one point during Wednesday's impeachment debate, Rep. Hank Johnson, D-Ga., argued that if anyone believed that the threat to free elections is not real, "I'd urge you to come down to Georgia, find a black man or woman of a certain age, and they'll tell you the danger is real." His Republican colleague and fellow Georgian Rep. Douglas Collins then got up and noted that since 2014, participation among minorities has "risen double digits. I'm very proud of what Georgia is doing to get everybody to the poll." That exchange came not long after a federal judge allowed the state of Georgia, controlled by Republicans, to expel 300,000 people from the voter rolls.

With President Donald Trump in an unusually weak position for an incumbent president running for reelection and the widespread understanding that the Republican Party is living on borrowed time demographically, with its almost entirely white base of support, voter suppression could become more important to the GOP's election plans than ever.

And purges are a key component of that strategy. Many states operate on a "use it or lose it" principle: If you haven't voted in a couple of elections, the state sends you a notice, and if you don't respond, they strike you from the rolls. Then the next time you show up to vote, you find that you're no longer registered.

In Wisconsin — a key battleground state and ground zero for Republican voter suppression — a state judge just ordered 234,000 names removed from the rolls, ruling that when the state sends voters a notice that they're in danger of being removed, they should have only 30 days to reply (a detail the notices did not inform voters of). Democratic state officials have filed suit in federal court to stop the purge.

But they may not succeed. Last year the five conservative justices on the Supreme Court upheld a similar Republican-ordered voter purge in Ohio. Research had shown that the purge was much more likely to sweep out Democratic voters, who are more likely to vote sporadically.

Republicans deny that they have any partisan motives; they claim that voter purges are just a way of cleaning up the rolls. But we all know the truth: If purges didn't work to suppress Democratic votes, Republicans wouldn't be so eager to do them.

But what about Collins's argument? Does the increased turnout in Georgia, which happened despite the fact that Brian Kemp (then the state's chief election official, now its governor) purged hundreds of thousands of voters prove that purges aren't actually helping Republicans?

The answer is no, because those suppression efforts take place in a dynamic environment where they inevitably produce a reaction from Democrats. Faced with Republican voter suppression, Democrats usually put extra effort into registration and turnout drives in order to overcome it. That's what happened in Georgia, as Kemp's Democratic opponent, Stacey Abrams, mounted an enormous grassroots mobilization that wasn't quite enough to overcome Kemp's control of the election system. While we can't say for sure what the outcome would have been, we do know that tens if not hundreds of thousands of properly eligible voters were kicked off the rolls ahead of an election decided by 55,000 votes.

The only way Democrats can stop such abuses is to win in 2020, no matter how hard Republicans make it.

Paul Waldman is an op-ed columnist and senior writer for The American Prospect.