The Democratic alarm further spiked two days later, when Univision advertising representatives told the Biden campaign that spots already purchased to run during the Trump interview in Nevada, Arizona, Pennsylvania and Florida had been canceled — owing to a heretofore unannounced policy about opposition advertising in single-candidate interviews.

Univision also canceled a booking with Biden’s Hispanic Media Director Maca Casado to respond to the Trump interview after it aired on the network’s late news broadcast, according to people familiar with the details, who like others spoke on the condition of anonymity for this article because they were not authorized to speak publicly.