There's a world of difference between storming in and seizing power by articulating an alternative vision of the future, and taking the reins by sitting on your heels and watching your opponents crash under the weight of their own unprecedented hubris.
Two short years ago the idea that the Dems might pick up enough tightly gerrymandered seats to change the balance of power in Congress was almost unthinkable. But today the GOP finds itself burdened with the grinding pain of Iraq, the administration's trailblazing incompetence on issues from immigration to Katrina reconstruction and facing a base that's enervated by record spending and seemingly endless cronyism. Throw in a couple of high-level Republican perp-walks on various corruption charges and you have the makings of an electoral sea change.
Congressional Dems now have a 15-point lead over their GOP counterparts in generic polls, and the views of those who consider themselves "independents" is almost identical to the views of Democrats on the most pressing issues of the day. The conventional wisdom is now that the Dems have a respectable shot at taking at least one chamber of Congress (smart money's on the House).
Like you, I've been burned before by overly sunny predictions about how the criminal gang currently in power is about to go down. But for the sake of argument, let's say the Dems do come roaring in and take the House. What then? That's a question that's not being asked as often as it should be.