In this week’s election, Mr. McAuliffe won 200,000 votes more than Northam did when he won the 2017 election in a blowout. He won nearly 600,000 more votes than he did in 2013 when he beat Kenneth Cuccinelli II to become governor. He beat his internal turnout targets in Northern Virginia, Richmond and the Norfolk area. Turnout was strong in Black precincts, college towns and the suburbs, all traditional areas of strength for Democratic candidates.

Yet Mr. Youngkin still got more votes, buoyed by turnout near presidential-election levels across rural Virginia and better than anticipated numbers in the outer suburbs of Washington. He won far more votes than Mr. McAuliffe’s team or virtually any of the public polling had anticipated.

“We’re at a dangerous inflection point where we have one group of people who assumes turnout solves all of our problems and another group that wants to tune out whole swaths of voters,” said Guy Cecil, the chairman of the Democratic super PAC Priorities USA. “There are millions of people across the country who are inclined to vote for Trump or Republicans who don’t vote.”