Mrs. Clinton, following her 2016 defeat, was particularly focused on the data gap between Democrats and Republicans. In March 2017, just weeks after he had won election to become party chairman, Mr. Perez visited Mrs. Clinton in her Chappaqua, N.Y., home and received a briefing about what her plans to rebuild the party’s data infrastructure would have been.
That July, Mrs. Clinton publicly criticized the data she had received from the party while running for president as “mediocre to poor, nonexistent, wrong.” Clinton campaign veterans still privately seethe at President Barack Obama’s aides for allowing the D.N.C. to atrophy during his second term, leaving her campaign at a substantial disadvantage.
The election of “2016 was the ultimate moment of frustration because you have more and more resources going into these elections, and the entire progressive Democratic ecosystem was not on the same page,” said Stephanie Schriock, the president of Emily’s List, an organization that backs Democratic women running for office.
A demonstration of the Democratic Data Exchange conducted last week for The New York Times showed a dashboard that allows campaigns, state parties and independent organizations to sort voters based on categories including whom they support for a particular office — from president to state legislative seats and local offices — and what their comfort level is with voting by mail and whether they trust the Postal Service.
While campaign officials have long had access to that sort of information, Democrats have never before been able to share it across the party’s archipelago of allied groups. And in a year in which Democratic campaigns are eschewing door-knocking amid the coronavirus pandemic, information on individual voters views is a valuable commodity.
“The thing that is most predictive of if you’re going to vote in this election or vote for this candidate,” said Lindsey Schuh Cortes, the exchange’s chief executive, “is voter contact data where you’re literally asking somebody: ‘Do you support this candidate? Are you going to turn out to vote?’ This data is really helpful at the tactical level to figure out: ‘Who am I contacting? Who am I not contacting?”
Ms. Schuh Cortes said Democratic campaigns and organizations would also use the exchange to conserve their resources.