If he's your boyfriend, you start the talk like this: "I deserve to be treated politely, and you're not capable of that, so goodbye".
If he's your legal husband, you start like this: "My lawyer will be drawing up the divorce papers so you should begin packing".
And most importantly, you talk with YOURSELF. What is it that keeps you in a relationship with a rude man? You're not describing a generally nice person who had a bad day and was rude to a server in a restaurant, and that shocked you because 99% of the time, this guy is a decent, polite, even-tempered gentleman. You're describing someone who is basically cruel, and has been since you met him, yet you willingly entered into a relationship with him. I don't care if he buys you cars and houses and designer clothing, or if he looks like George Clooney, or if he's the heir to the throne. None of that is important when the heart of a person is cruel and rude and mean-spirited.
Did you think you could "fix" him? Did you think that being with you would improve his temperament? Did you think that his wealth or status would compensate for his rotten personality?
It doesn't work. You can, when you begin a relationship, make small compromises. Maybe you're a vegetarian and he has to have meat or it's not a meal, and you can introduce him to an amazing couscous and grilled vegetables plate and convince him to try one meatless meal a week. Or maybe you can convince your new guy that his favorite raggedy stained t shirt is not the best choice for date night, and tell him how handsome he looks in an ironed fitted shirt. But if "rude is the kind of guy he is", to the point where you can't go out in public with him, and where he's extremely verbally cruel to you, that's a different story.
Evaluate your own strengths and weaknesses, starting with your willingness to endure cruelty, your inability to speak up for yourself about an important issue, and being uncomfortable asserting your right to be treated politely and kindly. That's the bottom line.