It's okay to attempt to subvert the Bill of Rights, attack the 2nd amendment, surrender our soveirngity, and engage in all sorts of criminal activity as the politicians that do this are rarely held accountable. (McKinney did most of this too, but that's not why she was removed).
But what's 'not okay' is to challenge our elitist screw-party system.
Most who do this are removed from office (McKinney, Dornan, Traficant, Judge Moore, etc.....). A few renegades, like Ron Paul and Tom Tancredo, are still there, but the GOP is trying to oust them as well. And others who challenge the system, don't even fare that well (see Larry McDonald).
McKinney was used by those who don't want an investigation into 9-11 prior knowledge, which there was plenty of (James Bovard has documented much of it in "Terrorism and Tyranny"). A lot of the 'prior knowledge' stuff was starting to come out, and they used a polarizing figure like McKinney to lead the charge on the investigation. Then they turned on her, and forced her from office to send a signal to others who might want to deviate from the official party line on 9/11.
The end result was the Republicans who had doubts didn't want to be seen on the same side of an issue as a loudmouth Marxist like McKinney. And Democrats who had doubts didn't want to share her fate in being removed from office. It worked like a charm.