Drew Angerer/Getty

Is a lack of enthusiasm Hillary Clinton’s Achilles heel?

There is very little evidence that James Comey’s Friday letter has affected polling significantly—there were signs that the race was tightening before October’s final surprise landed. And the Clinton campaign, according to a front page New York Times report, is confident with one week to go, for good reason. The fundamentals favor Clinton, who has many paths to victory, over Trump, who has few. She look especially strong in “demographically diverse states” like Florida, even as less demographically diverse (read: old and white) states like Ohio and Iowa look like they may be slipping away.

But there are signs that enthusiasm for Clinton among would-be supporters has taken a nosedive. A Washington Post/ABC poll showed that the percentage of Clinton’s supporters who were “very enthusiastic” about her candidacy had fallen sharply since the Comey letter, from 51 percent to 43 percent. This does not mean that these people aren’t going to vote for Clinton, but it could still affect turnout. Very enthusiastic voters are most likely to engage in get-out-the-vote efforts, manning phone banks, knocking on doors, and driving people to the polls.

Make no mistake, Clinton’s GOTV infrastructure is significantly more robust than Trump’s, but a dip in enthusiasm could still hurt her by starving her campaign’s GOTV efforts of manpower.