Looking for diversity in the presidential race? It’s with Alexandria Ocasio-Cortez and other surrogates for the all-white top Democratic candidates

DENISON, Iowa – Only weeks after he ended his presidential bid, Julián Castro stood with his twin brother, Joaquin, at a Mexican restaurant here on a snowy afternoon — two Texans at ease in each other’s company, if not in Iowa’s low winter temperatures, ready to make another pitch.

Since he could not face President Trump in November, Julián Castro told the handful of voters assembled inside El Jimador’s slope-roofed, brick building, let Senator Elizabeth Warren do it.

“I ran for president because we wanted to bring about an America where everyone counts,” he said. “In order to do that, we need to make real improvements in this country, and we need a leader that sees herself as a president for everybody.”

When Castro launched his campaign last year, he strived to become the nation’s first Latino president, running as part of the most racially diverse slate ever of Democratic presidential candidates. But just like most of the other Latino and Black candidates in the crowded field, he dropped out after slamming against barriers — some personal, some deeply structural — to raising money and gaining support in the polls.