The durability of party control in America’s past is easy to miss because our political histories tend to be presidential histories, and the presidency has tended to be more competitive than control of Congress. But when you view political power through a broader lens, our era is an aberration. In this 150-year time frame, there’s no period where political control has been as tenuous as in the last four decades. And that’s true whether you’re looking at how often control of the government switches or how much power the majority party wields when it’s on top.
