Americans need to face reality: Russia isn’t just meddling in our elections with viral Facebook posts and Twitter hashtags. There’s plenty of evidence that Moscow is mucking around directly in the mechanics of our voting system, and that should worry us greatly ahead of the 2018 midterms.

What we’ve heard in just the past few days is alarming: The head of cybersecurity at the Department of Homeland Security, Jeanette Manfra, confirmed in an interview with NBC News that Russian operatives had targeted 21 states and that “an exceptionally small number of them were actually successfully penetrated.” Obama Homeland Security Secretary Jeh Johnson confirmed that Russia was involved in the scanning and probing of voter registration databases, while cyberexpert and former FBI official Clint Watts noted, “Right now we cannot ensure that the vote is accurate,” and that Russia’s goal is to undermine the confidence of Americans in their elections.

Since we know that an exceptionally small number of successes in a close election can make the difference between victory and defeat, the incentive for Russia to continue its efforts is strong. Combine this with the Trump administration’s stunning inability or unwillingness to deter and defend our critical infrastructure from future cyberattacks — or even acknowledge the 2016 Russian interference — Russia’s proven ability to impede or change votes in key elections would be a grave national security threat.