If Karl Rove’s resignation from the White House two weeks ago represented the removal of Bush’s Brain from the body politic of the US presidency, the departure yesterday of Alberto Gonzales looked more like the long-delayed amputation of a gangrenous limb.

The Attorney-General has been a toxic force in the Administration for the past year. His faltering performance over the dismissal of nine US attorneys has done untold damage to an already beleaguered presidency. His meandering series of contradictions over what he knew about the firings and his toe-curlingly embarrassing appearances before congressional committees to answer questions on the subject fatally undermined his effectiveness.

Most recently, the revelation that – while still in the White House – he tried to force his ailing predecessor John Ashcroft to agree from his sickbed to approve the Administration’s domestic eavesdropping programme (he declined) further damaged his reputation for honesty and straight-dealing.

Though he was doubtless the target of the usual partisan political attacks by Democrats, he had a troubling tendency to bring trouble to the Administration. Mr Gonzales has proved a heavy liability for Mr Bush and the Republicans and in important debates over terrorism laws and other judicial policy matters, a considerable asset for their opponents.

Perhaps the biggest surprise behind the resignation yesterday was that it seems to have been entirely voluntary.

Unlike the removal of Donald Rumsfeld as Defence Secretary last year – a decision made by Mr Bush in the teeth of growing domestic political fury over the Iraq war – Mr Gonzales was not forced from office.

In a somewhat testy statement yesterday Mr Bush said that he had accepted the resignation “reluctantly” and loudly bemoaned the fact that Mr Gonzales’s name had been “dragged through the mud for political reasons”. Other reports said Mr Bush had only “grudgingly” agreed to it when Mr Gonzales offered it last Friday.

It seems that the Attorney-General had finally decided after a summer break from the maelstrom of Washington that he could simply no longer tolerate the heat and opprobrium he generated.

Though Mr Bush may be disappointed, other Republicans are likely to be much happier. There is little more than a year to go in the Bush Administration, but there are still important political-judicial decisions in the Attorney-General’s in-tray.

Being able to confront these issues with fresh blood, someone not tainted by the US attorneys issue, will give the Administration and its Republican allies a much better chance of achieving their objectives.

Democrats will be seeking to make inroads over the next year into the panoply of antiterrorism legislation enacted by Republicans over the past few years.

There will be continuing fights over the domestic wire-tapping programme by which the US Government is permitted to eavesdrop on terrorism suspects communicating with US residents.

There are several important terror-related cases to be heard before the Supreme Court, perhaps the most important one relating to the inmates at Guantanamo Bay. That will require not only a Justice Department capable of making a persuasive case in court, but may also mean the Administration is forced to produce new legislation to deal with whatever the court decides. Mr Gonzales would have been more or less incapable of performing those functions. His successor at least will have a chance.

Then, of course, there will be continuing political battle over the controversial removal of the US attorneys. Democrats in Congress will continue to press the Administration on how the firings came about. The next Attorney-General is unlikely to be as compromised on the issue, or as incapable of defending it, as the outgoing one.

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