Yes, George W. Bush had won "with the largest number of votes up to that point in American history while racking up the seventh Republican win in the previous 10 races for the White House" . . . but the reality is that he would have lost to one of the most mediocre human beings on the planet were it not for a margin of less than 120,000 votes in Ohio.
And the Republican Party was able to prevail in that election and maintain majorities in both Houses of Congress only because the consequences of their most disastrous policy decisions (the Iraq War, Medicare prescription drugs, and amnesty for illegal immigrants) wouldn't be felt for another two years.
2006 was a far better indicator than 2004 of the GOP's long-term prospects on the U.S. political scene.
I think 2006 was the first in a 2 part referendum on the GOP. 2008 was a reaction to circumstances and a collective forgetting of what happens when you let liberals run the country.