He's only been impeached for it this year.
There is no oversight to be had in that kind of single-party state.
If you're wondering about what the end game of that sort of thing looks like, Putin's Russia laid out a roadmap for it.
[1] The actual mechanism with which he has done so is by not paying the prosecutors that were supposed to prosecute him. It's utterly insane - the criminals are literally running the courts.