It’s a politicians job to cater to the people who actually vote. Moderates vote so democrats cater to them.
Republicans took voters from democrats by running ads that blamed “radical leftists democrats and their progressive policies” for inflation and every other problem under the sun.
Along with the leftists that didn’t vote this was enough to give the win to facists.
This is how US politics ratchets to the right.
Because leftists don’t vote for politicians that must cater to more than just leftists to win.
Regulatory capture and citizens united both exist to undo those checks and balances. No system is immune to corruption.