It sure is. It's probably gotten worse with age. Stress also triggers stutters. Knowing he's under intense scrutiny from all sides on every word he speaks in public probably makes it worse. Especially after a lifetime of dealing with pudding brains associating a speech delay with failing mental acuity.
The wrong words come out sometimes even if you know what you were about to say.
This seems to be the case here as evidenced by the rest of the press conference being smooth as butter.
But no one seems to care how well things went when you have single phrase fuck up early on. Answering questions effectively and intelligently later on means nothing when you can focus on something that brings in drama points for your average voter to suck on ...
My man, stuttering is not the same thing as anomia or other (related) speech disfluencies. Even so, they are all neurological symptoms and tend to appear amidst neurological decline and dimensia, even if not exclusively.
It would be one thing if he were simply stuttering his words or misplacing nouns in a sentence, but he has also been forgetting things like the deaths of colleagues and mis-remembering when things occurred. You can pretend those are just silly mistakes that anyone could make, but you shouldn't act surprised when it causes people to lose confidence in him.
The reason that clip is so funny, is because you can talk with a stutter, it just takes some time to get all the spunds out. People with stutters know the word they want to use. They don't confuse words with each other.
Stutter and aphasia are two completely separate
phenomena in the brain. Biden isn't stuttering; he is mixing up names of people and can't remember their names. Mixing up Trump vs Kamala, Putin vs Zelensky (with Z literally standing next to him!!) - that's not a stutter.