From the same Washington Post article:
The "one-pager" outlines why, in his view, the losses were not particularly extraordinary and therefore not a repudiation of Bush: The loss of 28 House seats and six Senate seats is roughly comparable to losses suffered by the party in the White House in the sixth year of other presidencies and the same as the average wartime midterm. Moreover, it says, 23 races were decided by two percentage points or less, and it credits the "GOP Ground Game," the Rove-devised turnout machine. Overall, a shift of 77,611 votes would have kept the House in Republican hands.

Seems I recall that a shift of less than 1000 votes in Florida in 2000, and less that 5000 votes in Ohio in 2004 would have made Karl Rove less important than the period at the end of this sentence. Something about liars and damn liars comes to mind....