ust days after Donald J. Trump left the White House, two former contestants on his reality show, “The Apprentice,” approached him with a pitch. Wes Moss and Andy Litinsky wanted to create a conservative media giant. Mr. Trump was taken with the idea. But he had to figure out how to pay for it. This month, the former president found a way. He agreed to merge his social media venture with what’s known as a special purpose acquisition company, or SPAC. The result is that Mr. Trump — largely shut out of the mainstream financial industry because of his history...