Jim Burns, a spokesperson for Customs and Border Protection, told The Intercept that “U.S. Border Patrol checkpoints in the path of Hurricane Harvey in Texas will close as state highways close.” So in other words, as long as the highways are functional for evacuation, the Border Patrol will operate checkpoints.
Burns added that Border Patrol checkpoints outside the path of the hurricane would remain operational.
About 2/3 of the US population lives within "the border" so...