It's a pretty big one. DoD certified iPhones only for nonsensitive work (low-level clearance stuff). In contrast, the sort of work POTUS does will most certainl

It's a pretty big one. DoD certified iPhones only for nonsensitive work (low-level clearance stuff). In contrast, the sort of work POTUS does will most certainly be sensitive. For things of that sort, the operating system AND the hardware are extensively vetted.