They could break the system from the bottom but for whatever reason aren't.

Comfort. The system as it is, is predictable. Not just the voting public but members of Congress too. Good example the FED rate. At any point Congress could have put forth fiscal policy to address the looming monetary situation that quantitative easing was very clearly bringing. But they didn't because no one wanted to be the group that ended the party. Because what would happen if they implemented policy and then poof, slow down of the economy or inflation?

But of course we know what happened. No fiscal policy got implemented and basically we kept riding that gravy train till it was completely untenable. Then monetary policy had to be implemented. Then came a massive spike in inflation. Congress was so scared to implement any kind of policy that they basically ensured the thing they didn't want happening.

Then you've got folks like Senator Elizabeth Warren trying to blame the FED chairman and it is like, "No, you're inaction Senator is why the FED chairman must do the things he must do. All 100 of you are culpable in this, you all sat there and did nothing."

But of course one brings this up and some folks want to try and hijack it like "See both sides!" Or you get "No the other team is much worse!" And the reality is, most members of Congress are just too sheepish to implement any kind of bold policy. Because what if it doesn't work? There's the obvious bunch that are seen most often in the news, but there's way more members than the ones that seek out face time on the TV. And those are the majority.

The majority of Congress just wants to push the button they're told to push, collect their paycheck, and move on. And that is why we see no motion. The polarization is the visible figureheads battling it out, but the real culprit is indifference and a desire to maintain the comfortable world that has known qualities. Very rarely is actual original thought obtained in the US Congress.