(FOXNEWSINSIDER) - John Kerry used his commencement speech at Northeastern University on Friday to take a thinly veiled swipe at Donald Trump, saying, "Greatness isn't about bragging, it's about doing."
"There are no walls big enough to stop people from anywhere, tens of thousands of miles away, who are determined to take their own lives while they target others," he said.
The secretary of state noted that this year's graduating class represented students from nearly 80 different countries-- "the most diverse class in Northeastern's history."
"In other words, you are Donald Trump's worst nightmare," said Kerry.
He warned graduates not to take advice from "soundbite salesmen and carnival barkers."
Kerry also implored them to remember that "we're not exceptional because we say we are, and keep repeating it."
"We're exceptional because we do exceptional things," he said.