One day, Americans who were too young to have followed the 2016 campaign will look back and try to make sense of it. They will want to know how such a dangerous person could have gotten so close to the presidency — a man who spoke of abandoning our allies, admiring foreign despots, weakening constitutional rights, and serially molesting women.

Those future adults may also pose a more personal question to their elders:

Mommy and Daddy, what did you do in response to Donald Trump?

It will be a fair question. The reality is, Trump could still win. It is unlikely, yes, but the gift he received from a surprisingly bumbling F.B.I. shows that campaigns aren’t over until they’re over.

With seven days left, it is not too late for anyone alarmed by Trump to get involved. As it happens, Trump himself has pointed toward the best way to do so. Again and again, he has attempted to undermine democratic legitimacy, be it inviting foreign interference or flirting with voter intimidation.

The right response to anti-democracy is more democracy. It’s also the way to defeat Trump. His paths to the presidency depend on large third-party vote shares and low turnout.