On Friday, Hillary Clinton’s presidential campaign released an arresting new ad. In it, Joel Sollender, an American Jewish soldier who was taken prisoner by the Nazis, responds to Donald Trump’s infamous claim that he doesn’t consider John McCain a war hero because “I like people that weren’t captured.” Here’s what Sollender said:

Sollender, who will soon turn 92, lives in California and has been speaking out against Trump and his candidacy for over a year, which is how the Clinton campaign found him. “I was very pleased that they contacted me and that I had a chance to voice my opinion,” he told me. Sollender worked for two hours with the film crew to produce the spot. The online ad runs for 90 seconds, while a 30-second version is now airing on TV. It has already gone viral and been viewed hundreds of thousands of times.

Something that didn’t make it into the short clip, Sollender said, was his fear at the time that the Germans would discover that he was Jewish. “As a prisoner of war, and being Jewish, I had some concerns about my dog tags, which were obviously marked ‘H’ for Hebrew,” he recounted. “But they never looked at them. I had blond hair and blue eyes and spoke a little German, so it helped me along.”

“I was a pretty lucky guy to do what I did and get away with it,” he continued, “and come home safely and have a more or less charmed life ever since.”

Sollender has been so vociferous this election because he has been deeply disturbed by the dark resonances he has perceived accompanying Trump’s ascent. For reference, he pointed to Sinclair Lewis’ 1935 novel, It Can’t Happen Here, which chronicles the rise of a fascist demagogue to the presidency of the United States. “There are indications that it could happen here,” he said, “and I’ll do whatever I can to stop it.”