NPR News Now covers President Trump's defense of a controversial Ohio gubernatorial ad and the Supreme Court's ruling on student ID voter verification in New Hampshire. The broadcast also reports on El Salvador's military operation to rescue hostages in Haiti, Mark Zuckerberg's agreement to pay California's proposed billionaire tax, and a new cancer vaccine that significantly reduces melanoma recurrence. Additionally, the episode features astronomers' revised dating of Van Gogh's "Starry Night" and New York City's ban on horse carriage rides.