If, as I’ve been arguing, Gary Johnson’s presence in the race slightly helps Hillary Clinton— because Johnson’s support, although drawing from both sides, draws slightly more potential Trump voters than potential Clinton voters, due to Trump’s fragile hold on parts of the Republican coalition– then the other side of the coin is that a decline in Johnson’s support disproportionately helps Trump.

These are drawn from the 538 poll averages. The last undated frame is from today– the day when 538’s now-cast as suddenly flipped to saying “if the election were held today, Trump would win.”

In the last month, Clinton has declined by 1.6%, Johnson by 1.9%. Trump has risen by 3.9%, a little more than the sum of those declines. Across the more recent two weeks– Clinton’s supposedly terrible stretch– Clinton has basically held steady. Trump’s rise has been at Johnson’s expense.

For people who keep not believing that a strong Johnson helps Clinton because The Millennials, see this. Young white voters act more like white voters than they do like young voters. Mitt Romney won among young white voters. Up until now, Trump’s solid lead among white voters was not reflected among young white voters. That might well have been a Johnson firewall– one that, at least as of today, seems not to be holding up.