US presidents stay in the White House for eight years if they are lucky. Even then, their power wanes considerably in their second term as George Bush is finding out.
The Iraq war has gnawed away at his popularity while Hurricane Katrina has savaged his reputation as much as it has ravaged New Orleans.
But suddenly, Bush has been presented with an opportunity that most presidents can only dream of. With the death of the highly conservative chief justice William Rehnquist just days before Senate confirmation hearings for John Roberts, Bush can nominate a second judge to the supreme court.
No sitting justice has died while in office in more than 50 years, and no president has installed two newcomers to the court at the same time since 1971, when Richard Nixon appointed Rehnquist to fill one of a pair of vacancies.
For Bush, the situation represents a rare chance to try and shape the court in his own conservative image and leave his most lasting legacy on America. It is also an opportunity to claw back the political initiative. Bush has already nominated John Roberts to succeed Rehnquist as America's top judge, a decisive act that contrasted sharply with the dithering after Katrina.
With the Roberts vetting process well advanced and his confirmation generating little opposition, such a shift could guarantee that a chief justice would be in place when the court opens its term early next month to consider important cases on abortion, assisted suicide and antitrust.
Although presidents like to nominate justices that they think reflect their political leanings, it can be very hit and miss. Appointed chief justice in 1953, Earl Warren turned out to be much more liberal than expected. He was involved in several landmark decisions including Brown v. Board of Education, which overturned the segregation of public schools; the "one man one vote" cases of 1962-1964, which dramatically altered the relative power of rural regions in many states; and Hernandez v. Texas, which gave Mexican-Americans the right to serve on juries.
Warren Burger, appointed chief justice by Richard Nixon in 1969, also disappointed conservatives. Burger did not move to oveturn the major decisions of the Warren court and in the most controversial ruling of his term, Roe v. Wade, Burger voted with the majority to recognise the right to abortion.
More recently, Justice Anthony Kennedy, who was appointed by Ronald Reagan, has pushed the court to defend homosexuality and abolish the juvenile death penalty.
In recent years, the court was evenly balanced between liberals and conservatives, often ruling 5-4 on important cases. But if Bush has his way, the court could take a decisive shift to the right.
