PHILADELPHIA — Bernie Sanders made a surprise visit this morning to the restless California Democratic delegation, telling them, “It’s easy to boo, but it is harder to look your kids in the face who will be living under a Donald Trump presidency.”

After having little luck suppressing the heckling from his passionate supporters at the opening of the Democratic National Convention on Monday, Sanders made a second appeal during the California delegation’s breakfast.

“What we must do or forever look back with regret is defeat Donald Trump,” he said, eliciting boos from the Bernie-or-bust supporters who crowded the stage.

The job of his supporters, he said, is to “give people a progressive agenda.”

Yet again, however, Sanders’ appeal had little effect on a forceful group of about a dozen or so supporters among the California delegation who booed down U.S. Rep Xavier Becerra, a Clinton superdelegate, and tussled with fellow Sanders delegates during the breakfast meeting.

“You’re ridiculous!” one Sanders delegate told the protesters at the front of the stage, echoing comedian Sarah Silverman’s line to diehard delegates Monday night at the convention. “Get out of the way!”

One of the Bernie-or-bust Sanders supporters, Alexis Edelstein from Southern California, said he was pushed by another delegate at the stage.

“Don’t ever touch me again,” he yelled at the delegate. Another shouted back, “Don’t threaten!”

Sam Hindi, a 54-year-old Sanders delegate from Foster City, said he and fellow delegate Lenny Siegel of Mountain View had met with a die-hard Sanders delegate for lunch Monday at the Reading Terminal Market and thought they made progress on working together. But it didn’t look like it Tuesday morning.

“Today they came back stronger,” Hindi said, “but I think the message will resonate.”

Contact Julia Prodis Sulek at 408-278-3409. Follow her at twitter.com/juliasulek