NPR News Now covers the start of the Republican midterm convention in Dallas, where President Trump aims to energize his base amid political headwinds. The episode also reports on an Anthropic researcher’s resignation, citing fears that AI development poses catastrophic risks to humanity. Additionally, it highlights the release of toxic air quality records from 9/11, prompting FDNY union leaders to demand answers about ongoing health impacts. Other stories include a cyberattack forcing early school closures in Massachusetts and questions over Trump’s $45,000 holiday gifts to senior aides.