Vermont Sen. Bernie Sanders made an appearance on CBS’s “The Late Show” with Stephen Colbert Monday evening, his first guest interview with Colbert since President-elect Donald Trump was announced last week as the U.S. presidential winner. Sanders met with Colbert to promote his new book, “Our Revolution,” which debuts Tuesday.

“Now that the results of the election are in, any thoughts about changing the title of the book?” Colbert quipped, not wasting any time.

“Now, more than ever, ‘Our Revolution’” Sanders, who lost to Hillary Clinton in the Democratic primary, responded. The initial exchange set the tone for the 5-minute late-night television spot.

Sanders spoke to his sense of optimism despite the end of his campaign and discussed his hopes for the Democratic Party. “The Democratic Party cannot be continued to run by, what I call, ‘a liberal elite,’” Sanders said. 

The former Democratic presidential candidate went on to clarify that the party needs to “transform itself” to be one that “opens the door,” to the working and middle classes and young people.

“Trump’s views are a minority. People do not think we should give tax breaks to billionaires – they do believe we should raise the minimum wage and have pay equity for women,” he said.

Sanders urged people to become more involved “in the political process,” moving forward. “Stand together and fight for a government and an economy that works for all of us,” he said. “When millions of people stand up and fight back, we will not be denied.”

Sanders said in an op-ed piece last week in the New York Times that he would keep "an open mind to see what ideas Mr. Trump offers" and expressed an interest in seeing how the two could work together in the future.

"He would do well to heed the views of progressives," Sanders wrote of Trump. "If the president-elect is serious about pursuing policies that improve the lives of working families, I'm going to present some very real opportunities for him to earn my support."