Sen. Bernie Sanders shot back at critics of his economic proposals at a press conference at the Institute for Research on Labor and Unemployment at UC Berkeley Friday evening.

The senator, who was introduced by Professor Robert Reich, kept his prepared comments to economic issues. Reich, formerly the U.S. Secretary of Labor, has endorsed Sanders for president but clarified that the press conference was not an endorsement from the Institute or Berkeley.

Sanders echoed his comments from the campaign trail about making tuition free at public universities.

“Right here at the University of California at Berkeley, I believe that in the year 2016, public colleges and universities should be tuition-free and we should lower student debt,” Sanders said. “Are these radical ideas? These are not radical ideas.”

During the question and answer portion of the conference, Sanders returned to his tuition plan. His frustration with Wall Street and some of his colleagues in Washington surfaced as he detailed his plan to cover those tuition expenses.

“We pay for it through a tax on Wall Street speculation,” Sanders said, raising his voice. “What the conventional wisdom is about Wall Street’s greed and illegal behavior that destroyed the economy — of course we’re going to bail them out. Why would we not bail them out?

“But young people who desperately need a good education — of course they should leave school $50-or-$70,000 in debt. Why would we help them?”

Tuition at public institutions across the country, including UC Berkeley, continues to rise as job growth begins to falter. The U.S. Department of Labor Bureau of Labor Statistics recently reported that the economy added approximately 38,000 jobs in May. Though that drove national unemployment down to 4.7 percent, it represents a downward trend in growth over the past three months, Reich said during his introductory comments.

The Sanders campaign has been barnstorming through California over the past few weeks, with the presidential hopeful estimating that by Monday he will have spoken in front of approximately 250,000 Californians. Sanders visited nearby Oakland for a rally on Memorial Day, reportedly attracting about 20,000 people.

His Democratic competition, Hillary Clinton, is campaigning across the state ahead of the June 7 California primary elections. She was scheduled to speak in San Bernardino, Woodland Hills and Santa Monica on Friday. Sanders trails Clinton by more than 250 pledged delegates and nearly 500 superdelegates, unelected delegates free to support any candidate they choose for the Democratic Party nomination.

Sanders declined to comment on the Democratic National Convention, where the party’s candidate could be selected if the candidates do not secure enough delegates, insisting that he wanted to stick to economic issues and avoid discussing party politics.

However, he repeated his conviction that there is a path forward to make a university education more affordable.

“We are the richest country in the history of the world,” Sanders said. “We will not succeed unless we have the best-educated workforce in the world.”