"The Democratic Party's message is not being heard from us. It's being heard from others," Kamala Harris, the attorney general of California who's widely viewed as a rising star in the party, told me. She and many other Democrats point to the success of minimum-wage ballot initiatives in several states as proof that the same voters who chose Republican representatives actually wanted Democratic policies.

This is a selective reading of the midterm results, to say the least. But to Harris, there was no question of changing the party's positions. "We need to stick to our values," she said. "Some would argue that when we don't do that, we lose."

This refrain could be heard over and over from the progressives who spoke at the summit—from Massachusetts Senator Elizabeth Warren to New York Mayor Bill de Blasio to climate-focused billionaire Tom Steyer. "Our agenda is America's agenda," Warren told the crowd. De Blasio said the Democrats who lost had failed to acknowledge and address "the inequality crisis." The Democratic brand, he said, had lost all meaning: "We're literally unidentifiable to the public." he said.

Though these figures are usually characterized as the party's leftist wing, CAP is squarely in the Democratic Party's mainstream, with deep ties to the Obama administration and the prospective Hillary Clinton presidential campaign. Another of the day's panelists was John Podesta, currently a counselor to Obama, formerly a president of CAP, and likely a future chairman of the prospective Hillary Clinton presidential campaign.

In the afternoon, Steyer—who poured tens of millions into the midterm elections only to see almost all the candidates he supported lose—spoke on a panel about climate. Carol Browner, the former administrator of the Environmental Protection Agency, applauded his work: "You made climate a part of this election debate, and we thank you for that."

Later that same day, the Senate would fail to pass a bill authorizing building the Keystone XL oil pipeline, which Steyer ardently opposes. Nonetheless, 14 Democratic senators supported it. Steyer was asked if that bothered him. He paused for a long moment.

"No," he finally said. "When we look around the country at the states where we've been active, being wrong on these issues has not paid off for anybody." Steyer added, "Not standing up for the things you really believe to protect yourself is not a winning strategy."

To Republicans, of course, this election looked very different: a definitive repudiation of President Obama and his policies, which he explicitly said, in an October speech echoed in a thousand campaign commercials, were "on the ballot." But Democrats insist this was not really the case—that voters, discouraged by gridlock or confused by Republican obfuscation, had trouble discerning what the parties stood for, and cast their votes—or stayed home—for other, murkier reasons. "A lot of people felt that this was an issue-less election," Neera Tanden, the president of CAP, told me, noting many pundits described it that way.