Our Separation of Powers Presidential system is supposed to prevent any one person or small group from seizing control over American government. By constraining executive power with independent legislative and judicial branches that supposedly prevent abuses and excesses. Our federal system puts constraints on the power of the central government, reserving rights and powers to the States.
From the standpoint of the Eighteenth Century, the Separation of Powers system looked like it offered more benefits than problems. Disconnected from the rest of the world by one, and later two, oceans, the United States could afford to bumble and squabble. The only real threats were armed enemies, and nobody would prevent war against them.
The modern world is a different and faster place. Air travel, mass communications, modern weaponry, and a global economy have meant that problems move faster than our multiple veto points can move policy. Like many state systems, ours is designed for conventional interstate war, and that’s an obsolescent threat.
Not only can problems like climate change and gun violence fester and worsen while corporate lobbyists use our veto points to stop effective action, the lack of coherent policy breeds a dissociative type of politics where the bases of both parties see themselves as in opposition. The voters never get to see an ideology enacted, so festering ideological disputes are never resolved. As you can see in the contemporary conservative movement, the incentives are to become more and more extreme, using the language of oppressed minorities to ratchet the rhetoric more and more.
Now, even with one-party government, the State is paralyzed. We narrowly avoided a government shutdown over the weekend. Under conditions like these, it’s easy to see why every American-style government on Earth has collapsed into some kind of discontinuity, coup, crisis, or civil war. It’s also worth noting that, although our system was supposed to protect the people from excesses of government power, the United States has amassed a series of atrocities worthy of its status as a great power.