Donald Trump’s attacks on four freshmen congresswomen of color—his use of the centuries-old insult to the unwanted that they should “go back where they came from”—is nothing less than a declaration of war on our very democracy.

True, this attack was racist, painting the women as outsiders because they are not white. Yes, his defenders accused the women falsely of being “communists” and “socialists,” of “anti-Semitism,” and of “hating America.”

But it’s much worse than that. It is a rebuke of the most fundamental tenet of our constitutional democracy that our citizens decide who shall represent them, that the voters—not the president—are the supreme authority of this land.

These four women were duly elected by majority vote (unlike Trump’s) to represent congressional districts in Minneapolis, Detroit, New York City, and Boston. Thus their authority is comparable to his. Neither he nor the howling fans at his rallies have anything to say about who will represent those voters.

But all that means nothing to him.

“They should go back where they came from.” And he doesn’t mean Minneapolis, Detroit, New York or Boston.

His eager incitement of his crowds to shout such ugly phrases is more than dangerous. It demonstrates his willingness to use democracy when it suits him and to discard it when it does not. And that is a characteristic of dictators. Recent history shows us that most dictators used democracy to gain power before rejecting it.

The reckless hurling of hot-button labels to ignite fear and hate in the crowds is another characteristic of dictators. Without precision he and his supporters pinned labels like “communist” on the women to reduce them to symbols of some vague evil the crowd little understands.

That is the dictator’s way of igniting the fire of hidden resentments harbored and repressed over years, then suddenly encouraged, usefully implying the threat of violence at the leader’s instigation. One saw it played out in twentieth century Europe and saw it smoldering on Wednesday in North Carolina.

The Republican Party again this week served unmistakable notice by its silence that it has willingly become the Trumpist Party, supporting and defending whatever he does without distinction.

Trump has cleaved our country into two camps who grow more furiously opposed with every passing day. He hints darkly that if he is removed from power there will be violence in the streets, and he loves a showdown. Thus he gives license to his more violent supporters to act upon their resentments.

And that seals our endangered democracy into a full-blown emergency. Nothing can save it now but the voters—not our institutions, our wounded media, our compromised Justice Department, our one-armed Congress.

If this democracy is to be saved from Trump, from his mindless followers in Congress, at his rallies, in the Justice Department, and ultimately in the streets, it must be saved by voters in 2020.

They must stay angry and resist the lethargy of Trump fatigue. Defenders of democracy, regardless of party, cannot afford to rest.