Aggressive dogs are often abused dogs
That's true. When you see a well trained dog, they aren't scurrying back and forth like that. They look at the human holding their lead and stay next to them without pulling the human in directions they don't intend to go. Trained dogs understand to "heel" and have been conditioned to know when they are not obeying.
Your video shows Biden treated his pet like a household object and not a powerful dog breed that requires discipline and socialization.
I worked with my GSD from the time he came home until he was 2 years old instilling the basic behaviors I wanted. He became a great family pet -- gentle, playful and aware that biting even in fun was not tolerated. He became very sensitive to my voice and commands. He knew when he did something good, and when he needed to adjust his behavior.
i had a vet tell me that when she read there was a German Shepherd on her schedule, she was very anxious. About 10 minutes into the exam, she said I have probably the best behaved German Shepherd she's ever treated. He had an ear infection, which normally causes the dog to be uncooperative and defensive when their ears are touched. He was just was obedient when she cleaned his ears as the rest of the exam.
It bothers me to see the leader of the country unable to accomplish what I did with just time and consistent training, especially when he can afford the best trainers in the country (world?).
I took my disobedient beagle to dog school. #1 lesson was that the school is for the owners. It's up to the owners to work with the dogs every single day to teach them the lessons being covered each week in class.