Oprah Winfrey was a surprise guest Wednesday on Night 3 of the Democratic National Convention in Chicago, delivering a rousing speech that highlighted the differences between Kamala Harris and her GOP counterpart. Winfrey, who has kept a low profile in politics so far this election cycle, called on viewers at home and the Democrats at the United Center in Chicago to keep faith in “the best of America” to help the country endure through this period of bitter partisanship. Like other speakers, Winfrey sounded the alarm on the agenda articulated by former President Donald Trump and other far-right forces.

“People who would have you believe that books are dangerous and assault rifles are safe,” she said. “That there’s a right way to worship and a wrong way to love.” Winfrey didn’t cite Trump by name but there was no doubt about her target.

Beware of politicians “who seek to first to divide and then to conquer,” she said. “When we stand together it is impossible to conquer us.” Winfrey cited the life story of Tessie Prevost, an activist who helped integrate schools in New Orleans as a 6-year-old in the 1950s, against the threat of snipers.

Citing the work of forebears such as Prevost, who died last month at age 69, Winfrey called on Americans to strive for greater unity. “America is an onging project that requires commitment and being open to the hard work and the heart work of democracy,” she said. “Every now and then it requires standing up to life�.