Matt,
The main point here is the linkage to intelligence. If Trump simply said “Joe Biden got tongue-tied today. Come on Joe, run for President, so I can cream you”. There would be no issue, but when he throws in the IQ part, THEN you run into problems.
So yes, Biden makes gaffe. Some of them are funny, some of them are. not.
Biden does have to chew gum and rub his head at the same time, and probably wiggle his toes. On one hand, he has to focus on keeping his speech focused and pronounced words correctly, fluently, and timely, and at the same time, make sure he remembers what he wants to say. Sometimes we jump the gun in what we want to say, especially in stressful situations. Barack America is probably an example of him jumping the gun. I think he meant to say Barack Obama is a wonderful American.
Most stutters would NEVER want to run for President and would avoid public speaking in general. They know that it would put them in places, where they would easily mangle sentences, and would give rise to mockery. Basically you would be asking them to run into a burning building or play Russian Roulette. Biden deserves credit for having the nerve to actually go out in public and make his voice heard.
Normally I don’t talk about stuttering at all. I like to think I am just a normal guy, who talks sports, politics, movies, and so forth. But I just cannot stand the fact that Trump linked intelligence with proper speaking.
Most people do not realize that Biden is a stutterer. He like me, has gone through a lot of therapy and practice. For me personally, I use to stutter about 40-50% of the time, and now it’s only 8% of the time. Biden is probably the same deal. But the point here is that it doesn’t go away ever. You can mask it. You can work with a therapist to learn how to speak in sentences better or pronounce words better, but it’s still there.