>What was senate thinking
This is not comparable to how one gets elected to an upper house in most countries: https://en.wikipedia.org/wiki/Federation_council_of_russia#E...
These are rubber-stamping yes-men of a single party state, obedience is the only thing required, thinking is not involved.
Let's hope they get to explain that in the the Hague at some point.
Maybe they thought there would be a repetition of the rather clean Krim expedition.
Maybe the shadow elite are against the war.
I don't know.