Photo

Donald J. Trump on Monday criticized the system for selecting delegates in Colorado, where he was shut out last week, insisting that people in the state were “marching” and “going crazy” over a “crooked” system.

The front-runner for the Republican nomination lost dozens of delegates to a better-organized Senator Ted Cruz in a series of conventions in Colorado congressional districts last week. Mr. Trump recently brought in a veteran delegate wrangler, Paul Manafort, who has a wide purview within the campaign now. But despite nearly a year of campaigning, his team before Mr. Manafort’s arrival had not prepared for a delegate slog.

“The people out there are going crazy,” Mr. Trump said in an interview with “Fox & Friends” on Monday. “They’re going absolutely crazy because they weren’t given a vote.”

Later, he added: “They’re going nuts. They’re marching.”

Mr. Trump insisted the system is “crooked” and created by “hacks.” But his own team did not provide adequate resources or preparations with seasoned hands over many weeks for some of these state contests. He recently made changes to his team after a double-digit loss in Wisconsin, where a “strike team” of top aides loyal to Mr. Trump’s campaign manager, Corey Lewandowski, did not net a victory.

The candidate went on to mention during the interview that two of his children did not switch their party registrations in time, to Republican from Democrat, to vote for him in next week’s New York primary. And he said they feel “very, very guilty.”

They were “unaware of the rules,” Mr. Trump said, adding, “Eric and Ivanka, I guess, won’t be voting.”

Mr. Trump told the hosts that his understanding was that registration needed to be changed roughly a year ago. In fact, the deadline just passed in recent days for new registration; for changing existing registration, it was October 2015.

Mr. Trump’s eldest three children have been prominent surrogates for him on the campaign trail, particularly Ivanka Trump. She has been the star of how-to-caucus videos that her father’s campaign used in states like Iowa.

Meanwhile, Mr. Trump again bemoaned the fact that the interrogation tactic known as “waterboarding,” which has been denounced as a method of torture, is not allowed to be used, saying it’s adding to an inability to combat the Islamic State.

“We won’t use strong tactics, whether it’s this or other things,” Mr. Trump said. “Can you imagine these ISIS people sitting around eating” and laughing about the United States not using waterboarding, he added.

He also criticized Mr. Cruz for a “hatred” for New Yorkers, evidenced by his “New York values” remark at a debate in February, eight days before that state’s delegate-rich primary in which Mr. Trump is still trying to reach the needed 1,237 delegates to win the Republican nomination at the party’s convention in July.

Find out what you need to know about the 2016 presidential race today, and get politics news updates via Facebook, Twitter and the First Draft newsletter.