As if the president is going to literally be on the battlefield physically fighting ISIS in person? This criticism makes no sense otherwise.
Think about it. Conservatives have always railed against Obama's "weak" foreign policy, but nobody has ever said he lacks the physical strength.
Pretty obvious what Trump is trying to do here - he, for some inexplicable reason, thinks there are still some uneducated white men who haven't yet decided to vote for him. Weird strategy. But then again, he's a backer of ISIS, so it's only to be expected that his ideas don't make much sense.
That is an excellent point.