When someone hit me for wearing a MAGA hat in Berlin I just twatted them back. Maybe it's a Brit thing or possibly I'm just a thug lol.
I don't think it is bullying to the extent that requires legal action but it is bullying behavior to knock off someone's hat to taunt them or make fun of them.
Yes, it is a misdemeanor assault. It does not actually take any contact to constitute assault, only causing a person to believe s/he is going to be assaulted. Lashing out at someone's head as he did is criminal assault. Grabbing the banner also constituted criminal assault or theft, either one. The man in the video committed criminal simple misdemeanor assault.
https://www.girlsaskguys.com/social-relationships/a7531-bullying-vs-harassment-vs-assault Bullying is similar to harassment in the fact that it tends to happened repeatedly. Harassment is definedas "...a course of conduct which annoys, threatens, intimidates, alarms, or puts a person in fear of their safety." The difference between the two is like the square and the rectangle. Bullying is the square. The added feature to bullying is that there must be and imbalance of power. This can either be something like a title; teacher, administrator, RA; a perceived imbalance of power; sibling; or a larger group of people. This means that bullying is always harassment but not all harassment is bullying. Assault is defined as, "Intentionally putting another person in reasonable apprehension of an imminent harmful or offensive contact. No intent to cause physical injury needs to exist, and no physical injury needs to result. So defined in tort law and the criminal statutes of some states." This means that if it is not a reoccurring issue, it cannot be harassment or bullying.
I bought a MAGA cap just to see how people would react. However, in the circles - including public - that I go it the result was not being negatively harassed. Rather, it was annoying for how many people wanted to strike up a pro-Trump conversation. An interesting legal question is what can a person legally do in response to someone who grabs or knocks off their MAGA cap? If someone grabs your cap - whatever it says - in response could the person kick the person in the groin or slug the person in the face calling it self defense or defense of your property - an instant response to being assaulted - or not? Years ago someone grabbed my favorite hat off my head from behind. I took it back and told him don't do it again. Later he did. I broke one of his fingers in response, telling him next time it will be his arm. However, it had nothing to do with politics. Rather it had to do with the other guy being an idiot. Way back then most people knew I was not someone to prick with. I learned that if you break someone's bone, even just a finger, that person will stop messing with me. Worked every time.
There are many levels of assault. The lowest level does not actually require any contact. Once injuries are caused, it goes up the ladder to a felony. Add a weapon to that and it likely goes up to attempted murder.
The common law definition of assault is "causing the apprehension of a harmful or offensive contact to one's person or property appurtenant thereto" IE you make someone flinch outwardly from something you know is liable to do that (like two for flinching style motions of the fist, or spitting at them etc) whether it would've caused harm or mere offense if it landed that's assault. Battery is the touching itself. A famous case in Texas involves a manager taking a plate of food from the hand of black nasa employee (engineer of some renown) during a meeting nasa was holding at the restaurant. He was invited, therefore had the right to be there, therefore had the right to the property which was snatched from him causing offense. So that would be common law battery, assault if they noticed you doing it and make some outward showing of apprehension of the contact.
Touching isn't an attack. Knocking it off somebody's head is. taking it off somebody's head is theft.