In what he billed as a major speech, Sen. Bernie Sanders (I-Vt.) pledged Wednesday night to hold president-elect Donald Trump to some of the promises he made while also standing up to any racism, sexism and bigotry that Trump may condone.

The speech was delivered at George Washington University and streamed live online.

Sanders, who nearly snared the Democratic presidential nomination before campaigning for nominee Hillary Clinton, read a snippet from his new book, Our Revolution: A Future to Believe In. In it, he declared, “We set the agenda for the America of tomorrow.”

His speech offered an indication of the new role the 75-year-old senator expects to play during a Trump presidency: speaking out early, often and loudly against any transgressions. Earlier Wednesday, the Senate Democratic leadership appointed Sanders to a new role — chair of outreach — that could give him a bigger stage from which to speak.

“What you will see on Capitol Hill is, many Democrats will be prepared to work with Mr. Trump if he turns out to be sincere about the promises he made during the campaign,” Sanders told the GWU crowd. “If those promises turn out to be hollow, if they were nothing more than campaign rhetoric, we will not only oppose his economic policies, we will expose that hypocrisy.”

Sanders cherry-picked all the Trump campaign promises he could support, challenging Trump to come through in standing up for the middle class and elderly, for raising the minimum wage and ending “disastrous” trade policies.

“He was saying he was going to be the champion of the middle class,” Sanders said of Trump. “We’re going to hold him accountable.”

“Mr. Trump said, unlike many Republicans — the vast majority of Republicans — he said he will not cut Social Security, Medicare and Medicaid,” Sanders said. “Pay attention to see what he does.”

Trump talked about a $10-an-hour federal minimum wage, Sanders said. “We will hold him to those words,” he pledged.

Then Sanders shifted to the agendas he doesn’t want to see Trump pursue.

“We will not be involved in the expansion of bigotry, of racism, of sexism,” Sanders said, to thunderous applause. “I know I speak for millions of fellow Americans. Mr. Trump, we are not going backward in terms of bigotry. We are going to go forward in creating a nondiscriminatory society.”

Earlier Wednesday, Sanders had called on Trump to rescind the appointment of Steve Bannon as his chief strategist and senior counsel, echoing the rest of the Vermont congressional delegation and many congressional Democrats. “The president of the United States should not have a racist at his side,” Sanders said Wednesday night.

He then called on Trump to pay attention to science, not the chief executive officers of the fossil-fuel industry, when it comes to climate change. “Climate change is not a hoax,” Sanders said. “Millions of us have got to stand up and tell Mr. Trump to read a little bit about science.”