On education, Sanders lauded for substance, knocked for cost

Democratic presidential candidate Sen. Bernie Sanders, I-Vt., smiles while the crowd chants his name during a campaign event on Sunday, Feb. 23, 2020, in Austin, Texas. (Nick Wagner/Austin American-Statesman via AP)

=Democratic presidential candidate Sen. Bernie Sanders, I-Vt., speaks during a Democratic presidential primary debate at the Gaillard Center, Tuesday, Feb. 25, 2020, in Charleston, S.C., co-hosted by CBS News and the Congressional Black Caucus Institute. (AP Photo/Patrick Semansky)

During the 2016 Democratic presidential race, when Bernie Sanders pushed making college free, it was seen as a radical idea from a fringe candidate.