By Clive Myrie
BBC News, Washington
Roberts was seen as an ideal candidate for the chief justice post
So the US has a new Chief Justice, John Glover Roberts Jr. He is the 17th man to lead the highest court in the land, coming at a time when turbulent social issues dominate political discourse here, like assisted suicide, same sex marriage and abortion rights.
Mr Roberts turned out to be the ideal nominee.
Originally put forward as a replacement for associate Justice Sandra Day O'Connor who is retiring, he was elevated to nominee for the top spot on the death of Chief Justice William Rehnquist.
In that role, for Republicans in the Senate and most Democrats he was the ideal candidate.
Mr Rehnquist was on the right wing of the court, so Mr Bush could afford to put forward someone of the same political persuasion.
But Mr Roberts is not an ideologue, as he stressed convincingly in his confirmation hearings.
Yes, he is conservative enough to please Mr Bush's political base, but not so right-wing that he offends most Senate Democrats.
That is why his confirmation was so convincing by 78 votes to 22.
No, the Roberts confirmation was the easy bit for Mr Bush.
Democrat gloves could really come off in the battle over whom should replace Ms Day O'Connor.
Sandra Day O'Connor's non-partisan vote was often decisive
In her 24 years on the court she was often the most influential judge, providing the crucial swing vote that decided numerous cases.
She neither leaned to the left or the right, but provided a range of opinions and votes that crossed the political divide.
Arlen Specter, the chairman of the Senate judiciary committee, will once again lead the confirmation hearings into her replacement.
He has already appealed to the White House to nominate someone in the same mould, someone who is not a right-wing hardliner, someone whose opinion cannot be prejudged, someone who will maintain the balance of the court.
Democrats have said this is an ideal opportunity for Mr Bush to bring together a divided nation, by nominating someone who politically is middle of the road.
But it is very tempting for the president to put forward a hard right-winger.
Bracing for fight
It is his chance to perpetuate his legacy long after he has left the White House, possibly for the next 20 or 30 years, and a hardline conservative would please enormously the Republican party faithful, especially those evangelical Christians who believe it is their votes that won him a second term.
But Democrats in the Senate are spoiling for a fight.
A hard-right nominee would see a messy and bitter confirmation battle and possibly the use of the infamous "nuclear option", where Democrats filibuster debate on the nominee to the point where the nomination has to be thrown out.
That is an extreme measure, one a few Democrats earlier this year said they would only adopt in an extreme circumstance.
Well that time could be now. Mr Bush is expected to name his nominee very soon.
He has a lot to weigh up and by all accounts has a shortlist of four or five names.
Polls suggest most Americans would like to see a balanced Supreme Court, and it is this fact that could decide his final pick.