ATLANTA — "I got 220,000 votes from people who also voted for Donald Trump," Jason Kander told the crowd at Netroots Nation on Thursday. "I did not do that by pretending to be a conservative Democrat."

The dimly lit ballroom of progressive activists cheered wildly.

Kander, who lost his race for Senate in Missouri to Roy Blunt in the fall, came to Atlanta bearing one clear message — the key to winning electoral victories is unapologetic progressivism, nothing less.

"Voters will forgive you for believing something that they don't believe so long as they know that you truly believe it," Kander explained, reflecting on his experience hearing from voters who offered him their support despite disagreeing with him on particular political issues.

Referencing how Democrats "[won] the argument over background checks" in his state, a dark-jean-clad Kander said that victory came because "we were willing to make our argument, to do it unapologetically, and that's what people are looking for."

The increasingly high-profile Democrat, who served as Missouri's secretary of state until January, looked back on the viral campaign ad that depicted him assembling a gun blindfolded, arguing his message resonated because he rebuffed the recommendations of supporters who suggested he pretend to be a Republican. "I didn't get into politics to play a character on TV," Kander quipped.

Now the president of Let America Vote, the former state representative said his group believes there should be "political consequences for folks who perpetrate voter suppression." Citing election laws and healthcare, he called on Democrats to make their argument to "absolutely everyone." The audience erupted in applause at his mention of a single-payer system.

"We have the wind at our back," Kander exclaimed from the podium.

"If we all work together, then we can save the American Dream from the nightmare that is Donald Trump," he assured the supportive crowd.

Emily Jashinsky is a commentary writer for the Washington Examiner.