2. Traditional polls are inaccurate: At the end of the 2012 Obama campaign, we were not using traditional polling for assessing the state of the race. Why? Because the methodology is less reliable than ever, given the wide usage of cell phones and the public’s antipathy toward answering a 20-minute survey. But even more important, traditional polling doesn’t get to what really matters in the last eight weeks of a campaign.

3. What matters most now is targeting: Or more specifically, targeting two groups: Hillary’s core supporters, who the Clinton campaign will make sure come out to vote, and leaning or up-for-grab voters, who are still in play.

4. Hillary’s campaign knows those voters, person by person: Obama’s campaign in 2008 and 2012 invented and perfected the use of “big data” for just this purpose. It combined the extremely sophisticated tracking of voters’ behavior with the most effective tactic of persuading and mobilizing voters ever invented: person-to-person contact.