Those who watched the October 19 presidential debate saw that Donald Trump said about Hillary Clinton, “She should not be allowed to run.” Here is one of the many news sources that show him saying that.
Under the United States Constitution, as interpreted by the U.S. Supreme Court in U.S. Term Limits v Thornton, anyone who is age 35, a natural born citizen, and a resident of the U.S. for at least 14 years, is permitted to run for President. Eugene Debs ran for president in 1920 while he was in a federal penitentiary for “espionage” (actually for opposing U.S. involvement in World War I). Vincent Hallinan, 1952 Progressive Party nominee, also ran for President while he was in prison.