Sen. Bernie Sanders (I-Vermont), who railed against the political establishment as a 2016 presidential candidate, said Sunday that he found President Donald Trump’s criticism of the “establishment” during his inaugural address “somewhat amusing.”

“I found it somewhat amusing that Mr. Trump, President Trump, was punching the establishment, but right behind him ... sitting in the VIP section, were billionaire after billionaire after billionaire, some of the most powerful people in this country, who over the last ten, 20 years have become much, much richer while the middle class has shrunk,” Sanders told CBS’ “Face the Nation.”

He said if Mr. Trump is serious about combating the establishment, he should make it clear that he will not do anything to jeopardize the health insurance of working Americans by telling people “he’s going to keep his word and that they do not have to live in anxiety.”

A day after more than half a million people showed up for the Women’s March in Washington and protests drew record crowds worldwide, Sanders said Mr. Trump should listen to the protesters’ message.

“Listen to the needs of women. Listen to the needs of the immigrant community. Listen to the needs of workers. Listen to what’s going on with regards to climate change,” he said. Modify your positions. Let’s work together to try to save this planet and protect the middle class.”

Sanders decried Republicans’ efforts to repeal the Affordable Care Act without a replacement ready to go, saying they’ve had plenty of time to come up with an alternative.

“It seems to me, and to the American people, you just cannot repeal the Affordable Care Act without a replacement,” he said. “Republicans have had eight years to come up with a replacement. I have not seen that yet.”

As for areas where he might be able to work with Mr. Trump, Sanders said it’s “absolutely right” that issues like reducing the cost of prescription drug benefits, infrastructure and trade issues could be points for common ground.

“In terms of infrastructure, clearly he is right when he says that our infrastructure is crumbling. We can create up to 13 million decent-paying jobs by rebuilding our crumbling infrastructure … I hope that he will work with us,” Sanders said. “We also understand that our trade policies are a disaster. Let’s see if we can work together on that as well.”