Nah, I know how to really piss 'em off. The definition of ‘white’ has always been cultural, not genetic. Look at how the Irish or Italians weren’t considered ‘white’ for many generations. So I propose we modify the definition of ‘white’ to deliberately exclude people with strong Southern heritage. Maybe we can justify it with racist psuedoscience. “No one whose ancestors who have lived in such a hot and humid area for so long can really be white.” If you have ancestors who have lived in the American South for more than three generations, you are now a person of color by default, regardless of your skin color. You no longer get to live in the ‘white’ club. If the Irish can be excluded from being white, so can the Southerners. Only people whose ancestors fought on the right side of the Civil War will get to call themselves white from here on out. We’ll even add a question to the Census that asks how long long your ancestors have lived below the Mason-Dixon line. Anyone who says three or more generations will automatically be classified as non-white, regardless of what they list their stated race as. We’ll take the thing from them that they value above everything else, their very whiteness.
Sure. But when I say, “professional hit man” I don’t mean a gangster, a mobster, or a spy. I’m referring to more of the professional hitman as seen in popular culture: https://tvtropes.org/pmwiki/pmwiki.php/Main/ProfessionalKiller
Think the trope in fiction. Someone wants someone killed. They find the shadiest person they can, like their tweaker cousin’s dealer. They then ask this shady person if they can put them in touch with a contract killer. Through the grapevine, they meet with someone who is literally a professional killer-for-hire. The usual trope is some extremely well-put together gentleman; he probably wears a 3-piece suit and black leather gloves. He probably views killing as an art form. He takes professional pride in it. He’s probably obsessed with expensive firearms and their various accessories, and he personally owns an arsenal big enough to take down the government of a modestly-sized city. Killing is his passion; he only charges at all because he has bills to pay like anyone else. The usual trope is to imagine someone as professional and presentable as the most formal lawyer or doctor you can imagine, except their business is killing.
While the real world version of a professional killer wouldn’t be so extreme, the core should remain if they are to be a professional killer. They don’t need to dress in a suit, have a private arsenal of rare expensive weapons, and speak in a British accent. But they should still meet the minimum definition of professional to count as a professional hitman. A “professional” is generally someone who offers a specific service to the public as their primary occupation. Lots of people know first aid. But only a doctor or a nurse makes medical care their actual profession. Most people can replace a light switch, but that doesn’t make them a professional electrician. A professional usually sees some higher purpose or artfulness in their services and seeks to provide them to all that can afford them.
Sammy Gravano was a mobster, a terrible human being, and a ruthless killer. But he was a mobster first, and a killer second. He committed numerous other crimes on behalf of the mob, not just murder. And he didn’t commit murders that weren’t at the behest of the mob. You, as a random stranger, couldn’t just knock on his door, hand him a bag full of cash, and get him to off someone for you. In fact, he would probably kill YOU just for trying.
Per OP’s original question, Sammy Gravano does not count. There was no way for some random person back during his day to find him, hire him, and have him take someone out for them. He was a mobster, not a professional hitman-for-hire. And that is a crucial distinction.