As I said above, I don't know if that would be a legal measure. But getting tax exempt status comes with strings attached, e.g. using money only for the primary, approved goals of the organization. Private travels of the president is not in the primary goals of the NRA. The NRA let that happen for multiple years. Therefore the NRA should lose the tax exempt status retroactively for that time and pay the back taxes. (Which, I guess, will make the question whether the NRA should be dissolved obsolete.)