Courtesy of Snopes:
The television series Trackdown really did produce an episode featuring a "Trump" character who came to town claiming that only he could prevent the end of the world by building a wall (and also sold special force propelling umbrellas to deflect meteorites). The episode (S1, E30) aired on CBS in 1958 and was titled "The End of the World," featuring actor Lawrence Dobkin playing the role of "Walter Trump." A synopsis of the episode from the Classic TV Archive reads as follows:
Walter Trump, a confidence man, puts on a long robe and holds a tent meeting in the town of Talpa. He tells the townspeople that a cosmic explosion will rain fire on the town and that he is the only one that can save them from death. Ranger Hoby Gilman attempts to prove Trump is a fraud.
Every time I think this whole thing cannot get any more surreal, well you know the rest.
I am beginning to think that Donald Trump is nothing but a fictional character himself cobbled together from bits and pieces of television series, comic strips, and science fiction novels.
(BTW did you notice that the TV character was sporting Trump's actual hairline?)