Yet when they want to push something unpopular like tax cuts for the rich, they manage to get it done. When it is bailing out banks or changing bankruptcy laws that hurt the little guy, they get it done. Trade deals done in secret no less, they get it done. Endless war... apparently not a problem.
The idea that they would if only they could but gee whiz they tried but they can't is a standard cop out that is part of the language the governing elites use for the public. Don't blame us because it is our fault sounds silly but that is what it boils down to.
Of course people like Sanders and Eliz. Warren may have trouble getting the lords and ladies to support raising the min. wage and other legislation not backed by oligarchy money. Our congress became privatized some time ago and except for a few holdouts like Sanders and Warren, they are obvious about it. So they keep a few old fashioned cop outs and excuses on hand for whenever it is necessary.
Being able to take effective action is the operating theory not the operating principle. Inertia is a steady state condition - the reality - that is only interrupted when oligarchic money wants legislation done. No money means little or no interest basically.
The only thing left is when there is no place left to hide from the public when it concerns something unavoidable. Climate change is like that. Sure congress will take action when inertia confronts unstoppable. A two foot rise in sea levels and you can bet that congress will be on it in a flash!!! Get that? In a flash (that means the 15 years prior to it when something could have been done to help avoid it, congress did nothing).
When it is already too late... you can trust that Congress will be first to take action.