Jay Cost is one of my favorite writers/thinkers anywhere. He's from the right side of the political aisle but his writing is really for anyone and everyone curious about elections and the American political system.
In practice, separating power has the effect of giving lots of people vetoes. It makes it easy to prevent change, very hard to enact it: for change to happen, all of those representatives who have the opportunity to exercise a veto must demure. This, of course, is exactly what happened with the immigration bill. It was proposed, and then Byron Dorgan - a single man from one of the least populous states in the Union - effectively vetoed it. None of this is coincidental. As a matter of fact, this kind of "nonsense" was exactly how Mr. Madison believed liberal, republican government would be preserved. It is in these seemingly infuriating actions that we can actually see the ingenious innovation of our system!
This is the choice that our founders made. They chose governmental "gridlock" and "failure" over programmatic efficiency and "success." Why? They feared that programmatic efficiency would enable one faction to railroad another, thus endangering true republican government. If no faction has control over another, true republican government is possible. The price we must pay is programmatic efficiency.
I must admit that I find myself disappointed when journalists with years of experience covering Washington watch our system stultify efforts to alter the status quo, and then declare - in so many words - that a failure has occurred. There was no failure here! This discourages me because proclamations of failure engender in the public a sense that our system is not working as it should when, in fact, it is working exactly as it should.
Our system is extremely complicated, our education system gives short shrift to civics training, and so there is a wide divergence between what the average citizen thinks our system was intended to do, and what it was actually intended to do. Misguided criticisms from journalists who look fondly upon those halcyon days of programmatic efficiency that never existed only exacerbate this disconnection.
Rather than bemoan the "broken" state of our government, let us recognize that this is exactly how our government was intended to function, and that - given that it has been functioning now without interruption for 150 years - there can be little doubt that this functioning has served us well.
When there is a nationwide consensus of significant size on the issue of immigration, then there will be reform. In the meantime, let's stop implying that our system has failed us. It hasn't. It's all part and parcel of the Madisonian system. Learn it, love it, live it. You have no other choice. It's not like you can change it!