Arguably President Bush's most important aide over the last few years, Karl Rove, has announced he is going to leave the White House at the end of the month. He's the latest in a series of senior administration officials to quit, as Bush's presidency nears the end.
It seems Rove has decided to go partly because there's not much left for him to do. His greatest achievement was being the key figure in Bush's two election victories, campaigns in which he had no qualms about fighting dirty - witness his team's trashing of John McCain's reputation during the 2000 South Carolina primary. Rove's magic touch disappeared though as the Republicans suffered defeat in last year's midterms, and so there's a serious limit to how useful Rove can now be, as well as (with a Democrat Congress) to what Bush can now achieve in his last 18 months in office. There's also the question of the extent of his involvement in the controversial firings of nine prosecutors, a scandal that's picked up from the Plame affair (which also involved Rove) as the big political sideshow in Washington.
To use a British analogy, Karl Rove is to President Bush what Alastair Campbell was to Tony Blair. And, just like Campbell, Rove in the end has had to resign because he became the story, and was such a controversial figure he was doing more harm than good to the administration. There's one more similarity between Rove and Campbell - Rove says he's going to write a book. It'll be eagerly awaited.