CLEVELAND — Donald J. Trump was told, no, it was not sensible to have Don King, the flamboyant boxing promoter, address the Republican convention. But Mr. Trump, who has repeatedly boasted of having Mr. King’s support, kept pressing the matter.

Finally, officials including Reince Priebus, the Republican national chairman, firmly explained to Mr. Trump why Mr. King should not be invited: He once stomped a man to death and was convicted of manslaughter. The party could not associate itself with someone convicted of a felony.

Mr. Trump eventually relented. Mr. King, a Cleveland native, will not take the stage.

But the exchange, relayed by three Republican strategists familiar with the conversations, highlights the difficulties that planners have had building a program for a presidential candidate who is as much an entertainer as a politician. After months of saying he wanted a convention that would feature the sort of “showbiz” that past party conclaves lacked, Mr. Trump will arrive here Monday for a more traditional gathering than he may have envisioned.