I'm currently on the move so I can't currently give more lengthy response, but these are the people. There's a growing right wing opposition to NATO, which now, might seem insignificant, but as the war drags longer and longer?
The US knows it can't drag the war on in perpetuity, and if support falls come time for the next election, this puts Democrats in a dangerous and weakened position.
I'd be interested to see what instances you're referring to in terms of the SU and China allying with other imperialist forces. The instances I can think, such as the Molotov Ribbentrop pact we'rent so much allying as it was a stalemate that allowed the SU to gather up it's arms. Even then, the SU ended up going to war against those same forces, which points to the reality points to how alliances with reactionary forces is ultimately short lived and can be dangerous.
I do think that Russia plays a progressive tole in today's landscape, but that's different than expecting Putin to liberate us from NATO.