Rival party is not equivalent to the cops.

Even if the rival party were to somehow control all 3 branches of government (which they will not), the voting records show a full 1/3 of American adults outright support this corruption (many of the cops themselves), and another 1/3 are willing to ignore it.

If you are in the 1/3 that does care about it, you are not going to have a good time trying to fight the other 1/3, many of whom make up the “law and order” department.

So the answer to both questions is a resounding no, because the world is more complicated than a comic book superhero movie.