Karl Rove, President Bush's close friend and chief political strategist, plans to leave the administration at the end of August, the White House said Monday.A longtime member of Mr. Bush's inner circle, Rove was nicknamed "the architect" by the president for designing the strategy that twice won him the White House.A criminal investigation put Rove under scrutiny for months during the investigation into the leak of a CIA operative's name but he was never charged with any crime. In a more recent controversy, Rove, citing executive privilege, has refused to testify before Congress about the firing of U.S. attorneys.