“Their authorization under the law regarding this case would be impeachment.”
Nobody, at the whitehouse or in congress, is following the law. If you follow “the law,” while your enemy obeys no law, you will lose. The only time you can possibly follow “the law,” is if you have enough firepower to enforce “the law.”
Strategically, you're obviously correct.
Tactically, balancing the logical follow-up of your argument with keeping the country intact is problematic.