While this article on "what went wrong?" last year is about Bush vs. the Congress, it really could be about any president since Watergate. The gridlock we've all come to know and loathe is of course far from new, but its origins are more recent, and more reasonable, than you'd probably first imagine.
Before Watergate, probably to combat the very things this article talks about, Congress had gradually structured itself so that most of its power was concentrated in the hands of just a few committee chairs. Presidents who really wanted something done met with perhaps 15 or so men (they were always men) and if he could get them to agree to it, it got done.
The zenith of this arrangement was during the Johnson administration. Between 1964 and 1968 perhaps the most powerful congressman (and senator) of the modern era was placed in charge of the presidency with a then-unprecedented electoral majority. Lyndon Johnson knew how the institution worked, knew the men who worked it, and knew exactly what was needed to get something, anything, done. The result was an era of Democratic power and unity not seen before or since.
Largely because of the disastrous excesses this concentration of power created in the Johnson and later Nixon administrations, Congress reformed itself in 1974 (the so-called "Watergate baby" era). The intent was to shatter the control of the comittee chairs and de-centralize decision making in the hopes of making the institution more representative of and compliant to the people. As with most attempts to change powerful structures, they succeeded, but at a cost they didn't foresee.
Instead of de-centralizing the power of committees, the reforms instead created dozens of sub-committees with weaker but still powerful chairmen. The "surface area" of power increased, allowing many more places for lobbyists and special interests groups to corrode the ability of the institution to act in a sensible and consistent manner. That is, when it could act at all, since much of the traditional gridlock of what we now experience as the federal government is traced directly to these reforms.
This is not to say the reforms were bad. After all, they were put in place to stop debacles on the scale of Vietnam, Watergate, and the "stagflation" of the early 70s from ever happening again, and at this they have succeeded reasonably well*. It does, however, mean that people have far less to fear from one party holding "all the cards", and far less to hope for splitting that power between the two parties.
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* Those who equate the experiences of 2001-2005 to 1968-1974 either have an axe to grind or aren't paying attention.