The system of governance we have today is one where representatives are in the long term accountable to the people, but in the short term look for support to various factions, either special interest groups (such as unions, the NRA, etc) or monied interests (such as companies, wealthy individuals, etc). These factions end up having an outsized influence on what representatives are chosen and they make any representative who wishes to support a policy that goes against their chosen factions pay a severe price for the disloyalty.