What the heck is that supposed to mean ?
He might have heart trouble he doesn’t know about?
What it means is if trump does not go to the convention with 50% +1 delagate the Republican party will not make him the nominee. The more candidates that stay in the race substantially reduces the chance that trump will make the needed delegate goal.
This whole plan was set up in 2012 by the RNC originally to make it impossible for Cruz to get the nomination. They knew he was going to run, somehow. So, they will use the same rules to block trump because they hate him just slightly less than Cruz and know from intensive polling he will lose against Bernie or Hillary and certainly Joe if he runs.
Remember, 50% +1 or 1237 delegates is the magic number.
The worst part(for trump) is if he does not make that number it will be too late for him to register in many states for a run as an independent. So the RNC gets rid of Trump at least for 4 years and by then he will be too old for another run.