Trump made a lot of gaffes, when he mispronounced words and names: " Take a look to the oranges, the oranges of the investigation , yosemnites Yosemnites , Bentannyahu, the United Shaish, six patients six patients to sick patients, traspants, anonimuss anominess and many others... Or the no sense things he said, "Biden has removed removable removables... ", " We will build a wall in Colorado ", in 1776 the army took over airports" , "in 1917 the Spanish flue ended ww2" , "My father was Germany" Ecc. And he said the last questions of cognitive test were really hard... Cognitive tests aren't supposed to be difficult... But no one say that Trump could have dementia. Stuttering is a speech disorder that involves frequent and significant problems with normal fluency and flow of speech. People who stutter know what they want to say, but have difficulty saying it. For example, they may repeat or prolong a word, a syllable, or a consonant or vowel sound. Or they may pause during speech because they've reached a problematic word or sound. Stuttering symptoms may include: -Difficulty starting a word, phrase or sentence -prolonged words or sounds -Repetition of a sound, syllable or word -Brief silence for certain syllables or words, or pauses -Addition of extra words such as "um" if difficulty moving to the next word The speech difficulties of stuttering may be accompanied by: -Rapid eye blinks -Tremors of the lips or jaw -Facial tics Later on in life  stutter can come back unexpectedly. You may not remember ever having a stutter as a child, or it is common that many people who grew up with a stutter avoid their problem words. You have spoken the same for so long and some added pressure or other reason could make the stutter reappear. I found some people on reddit who talked about their experience of stutter coming back. https://www.reddit.com/r/Stutter/comments/8lyhe5/why_has_my_stutter_come_back_over_the_last_two/Reddit https://www.reddit.com/r/Stutter/comments/bj8d6q/my_stutter_is_coming_back_and_i_dont_know_what_to/