Karl Rove will leave US President George Bush's side credited with near mystical and Machiavellian political powers and reviled by Democrats who repeatedly fell victim to his shadowy genius.
But the man dubbed "Bush's brain" and celebrated by the president as the "architect" of his two election victories also fell short of his cherished goal of forging a permanent, conservative Republican majority in Washington.
Rove, one of the most influential Washington players in decades, yesterday announced his resignation at the end of the month on the conservative editorial pages of the Wall Street Journal, after six-and-a-half years at the epicenter of Bush's stormy presidency.
Officially deputy chief of staff at the White House, Rove's was the hidden hand on the hard-knuckle politics which drove Bush through a disputed election win in 2000 and the aftermath of the Sept. 11 attacks in 2001.
Rove's legend was only slightly dimmed when the Democrats grabbed power in both the House of Representatives and the Senate last year.
He also leaves office with Bush's presidency apparently mired in a lame duck twilight, after the spectacular failure of immigration reform and with the entanglement of US troops in Iraq overshadowing the White House.
Rove will be remembered for putting an unyielding conservative imprint on Bush policy, from sweeping tax cuts and Supreme Court nominees to tapping the power of the religious right and social conservative voters.
Bush liked to call his chief political adviser his "boy genius," but opponents have preferred the Texas title "turd blossom."
Rove says he is leaving at the end of the month for family reasons, but there have been Democratic calls for his head ever since he was investigated over the naming of an undercover CIA operative whose husband was a leading opponent of the Iraq war.
While Vice President Dick Cheney's top adviser, Lewis Libby, was found guilty in court for lying over the leak, a special prosecutor decided there was no case against Rove who lived to fight a new political battle.
Congress is also demanding Rove's testimony over a row over the firing of federal prosecutors who critics say were sacked for political gain.
Rove helped Bush through Texas politics, the state governorship and to the ultimate prize -- the White House.
He used county by county mastery of the US political map to earn Bush his victory over Democrat Al Gore in 1999 and to return him to the White House ahead of John Kerry in 2004.