The Venezuelan people will march Wednesday for freedom and democracy. They will do so at the urging of the National Assembly—Venezuela’s legitimate legislature—and its courageous president, Juan Guaidó. As I told Mr. Guaidó last week, President Trump and the U.S. stand resolutely with the Venezuelan people as they seek to regain their liberty from dictator Nicolás Maduro.

The National Assembly has rightly called Mr. Maduro’s rule illegitimate, following a sham election last May. It has called for protests on Jan. 23 because...