You're surprised that politicians don't attach remotely detonated bombs to the laptops?
In particular remotely denoted "Kill" devices. Which destroy the entirety of the laptops contents.
Encryption by itself is likely not enough to secure the contents from a nation state actor.
Considering the competence of most politicians, I think it would easily solve a lot of problems if they did.
There is nothing remotely that important on the laptops in a typical Congressional office.
If you mean able to damage the holder, you'd need to triple-check they can't be unintentionally activated or activated by untrusted parties. Even if just a self-destruct, you'd need to double-check. Bricking the entirety of Congress' laptops have a lot of fun and profit potential.