As acting attorney general Sally Yates struggled to figure out how or whether to defend President Trump’s immigration order last weekend — while protests erupted at airports nationwide, immigrants were denied entry to the United States and civil rights lawyers rushed to court — two events helped crystallize her decision.

The first was a television appearance by Trump on the Christian Broadcasting Network. In an interview, he said that Christians in the Middle East who were persecuted should be given priority to move to the United States because they had been “horribly treated.”

The second was late Saturday night when former New York mayor Rudolph W. Giuliani appeared on Fox News. Giuliani said Trump wanted a “Muslim ban” and asked him to pull together a commission to show him “the right way to do it legally.”

“Those two things put the order in a very different light,” said a senior Justice Department official familiar with her decision. “Trump’s executive order appeared to be designed to make distinctions among different classes of people based on their religion.”