There are two absolute characteristics of all U.S. Senators: they are very stupid and they are very lazy.
I have observed Senator McCain. I do not beleive he is either stupid, or lazy.
He is obsessed with power, and believes he needs to lie to the American people to stay in power and do what he wants/thinks needs to be done.
I actually meant to write “they are very selfish” and “very lazy” and it came out wrong, so I think that fits better with your experience...the lazy comes from them doing no actual work of their own in their careers...