The US Attorney scandal broke in January 2007 and became national news by March. Karl Rove resigned on August 31, 2007, and Attorney General Gonzales was out by September.
However, Rove's slide into irrelevance had actually begun in 2005, as indicated by the Atlantic article from September 2007 that I quote below. Tom DeLay's legal troubles, which began in September 2005 and culminated with his resignation as House Majority Leader in June 2006, also undermined the possibility of achieving a "permanent Republican majority" through political means alone.
I would guess that Bush administration actions from late 2005 to early 2007 -- which included both pressure on US Attorneys to disenfranchise voters and a desperate attempt to push for war with Iran -- were intended as the opening moves in a bid for absolute power outside normal political channels. And after those efforts failed, they had no more tricks left up their sleeve.
http://www.theatlantic.com/magazine/archive/2007/09/the-rove-presidency/306132/
But within a year the administration was crumbling. Social Security had gone nowhere. Hurricane Katrina, the worsening war in Iraq, and the disastrous nomination of Harriet Miers to the Supreme Court shattered the illusion of stern competence that had helped reelect Bush. What surprised everybody was how suddenly it happened; for a while, many devotees of the Cult of Rove seemed not to accept that it had. As recently as last fall, serious journalists were churning out soaring encomiums to Rove and his methods with titles like One Party Country and The Way to Win. In retrospect, everyone should have been focusing less on how those methods were used to win elections and more on why they couldn’t deliver once the elections were over.
The story of why an ambitious Republican president working with a Republican Congress failed to achieve most of what he set out to do finds Rove at center stage. A big paradox of Bush’s presidency is that Rove, who had maybe the best purely political mind in a generation and almost limitless opportunities to apply it from the very outset, managed to steer the administration toward disaster.
= new reply since forum marked as read