Mark Cuban and Donald TrumpAllen Berezovsky via Getty Images; Jeff Kowalsky/AFP via Getty ImagesMark Cuban says Trump has turned the Republican Party into his own "family business.""RNC? Here comes the daughter-in-law. You know who's going to speak for him? His two sons," he said to CNBC.Cuban, a vocal Kamala Harris backer, has slammed Trump for his business ethics and core values.Mark Cuban said former President Donald Trump has made the Republican Party his "family business."In an interview with CNBC's "Squawk Pod" on Thursday, Cuban discussed the GOP presidential candidate with billionaire hedge fund manager David Tepper and SEC chief Gary Gensler."All we've seen Donald Trump do is hire his relatives," Cuban told Tepper and Gensler.