Kamala Harris’ running mate, Minnesota Gov. Tim Walz, will face a national audience that’s still getting to know him when he headlines the Democratic National Convention in Chicago on Wednesday night.

Walz wasn’t widely known outside of Minnesota before Harris chose him to join her on the Democratic presidential ticket. But they clicked when the vice president interviewed him, and she was impressed by his record as a governor and congressman — and the splash he made on TV. His attack line against former President Donald Trump and his running mate, Ohio Sen. JD Vance — “These guys are just weird” — spread like a prairie fire.