is it ever ok for a man to strike a woman with a hamburger?

No. Never acceptable. And honestly, it’s really not acceptable for a man to hit another man under those circumstances either. 

This was my thought too.

It's never okay to hit another person.

Whether you are right or wrong not wanting an apology I would ask you this, who is still suffering? You think about it everyday, does he?

You have not allowed yourself to close this episode, what do you want if an apology is not acceptable? What would bring you peace?

WTH? He hit you in a public place, over politics? Nope, not acceptable of course.

But... you're still angry about it after a year. What are you hanging onto, not allowing him to apologise? He obviously realises that he did a VERY wrong thing. I don't think you're "wrong" for not wanting to let him apologise, but I do think it would be healthier for you and your relationship with your friend and her family if you did.

Obviously, what happened to you was very wrong and not acceptable.

But I don’t understand why the issue has to be phrased like you phrased the title.

What does gender have to do with any of this?

Regardless of gender, no, it is not acceptable for one person to hit another person.

Why do people bring gender into that?

IMO, it is never ok for one person to hit another in anger. Male hitting another male or female hitting a male. OTOH, you knew before going they didn't discuss politics and you knew the dialogue was argumentative, what did you expect to gain by punching his buttons? I am not going to give you a pass at you continuing knowing he how he felt. IMO adults also don't make their dinner companions unhappy with dinner conversations either.

You do not have to accept his apology if you don't want. You do need to deal with your anger though. A year later you still think about it daily.

Your title is strange given the circumstance.

He shouldn't have hit you. You don't have to forgive him.

Thinking about it daily a year later needs to be addressed. That's not healthy for you.

I agree with everything elaine said.

And honestly now I'm scared for your friend. If he will do that to you in public over a trump comment what is he doing to her behind closed doors?

To answer your question, male or female, it is never okay to hit another person except possibly in cases of self defense or in order to stop a crime. I do admit having a bit of difficulty understanding whether he sucker punched you or smashed his/your burger in your face? Either is not okay, but one would have had me filing assault charges.

Totally inappropriate action - doesn’t matter whether male or female on either end.

I have to wonder about your friend, and if she’s ever been hit or if she lives with a fear of being hit.

For you, if you think about this every day, I do think you need to figure out how to move past this. Not so you can socialize with him or anything, because I’m not sure I ever would again, but so that it doesn’t live in your head forever. What do you need in order to put it behind you and move forward?

In this situation it is not ok to hit a woman. But really in this situation it is not ok for anyone to hit any person, no matter their gender. His reaction to what appears to be a civil conversation was extremely over the top. And I would not ever want to be near him again. I would do the exact same thing you are doing by keeping your distance from him. He could apologize all he wanted. I wouldn’t accept it, and I would still not have anything to do with him. I would also be extremely concerned that my best friend is the victim of some form of abuse within her marriage. Because if he did that to you during a dinner in public, I hate to think about how he reacts when his wife simply voices her dissent in their private home.

As to your question about whether it is ever ok to hit a woman, I think it is. I have never understood why it is ok to never hit a woman, but hitting a man is ok (it is not). But specifically, I think if a woman is going ape shit and beating the crap out of a man, the man should be able to physically defend himself if needed. Gender shouldn’t factor in.