Problem with the Merriam-Webster definition
The black community doesn't use this definition. The problem is that black people who are racist don't like being called racist so they changed the definition. To them, to be racist you have have the power to back it up. Since black people (at the time) didn't have power they claimed that a black racist should be called a reverse-racist. This was actually a brilliant move because they could hate other people based on race and they would have to be called reverse-racist, which "sounds" like they are the opposite of a racist. They can yell RACISM as loud as they want and nobody can use it against them. I'm not sure how the definition will work now that a black person is in power. They will probably have to redefine the definition again.