It's not border patrol. It's Immigration and Customs Enforcement. They have jurisdiction everywhere.

From the internet: Federal regulations allow the US Customs and Border Patrol to operate "anywhere within 100 miles of any US external boundary". "External boundary" includes the Canadian and Mexican borders, sea coasts and the great lakes; but it does not include airports. The zone does include many major cities, not because airports count but because many major cities are within 100 miles of of an external boundary. About two thirds of the US population lives within the zone. The CBP does not have the same powers in the zone that they have at the border. They cannot stop or search someone away from the border without reasonable suspicion or probable cause. (looks like the twin cities are closer to 150 from lake superior so not sure why they'd have any jurisdiction)

Even Border Chief was out harassing Uber drivers at the airport in Minneapolis. They’re just doing PR stunts with news team following them around.