By Matthew Davis
BBC News, Washington
The nomination to the Supreme Court of the conservative judge John Roberts, a lawyer with impeccable credentials, is being hailed by some as one of President George W Bush's shrewdest political moves.
Groups on the political right have already welcomed a nominee believed to hold staunchly conservative views on social issues.
Yet he was also considered one of the less contentious candidates for the hugely powerful and politically sensitive post.
The cautious response from leading Democrats augurs for a confirmation process that will certainly be robust, but is less likely to be the all-out war a more extreme candidate could have triggered.
However, Mr Roberts has only been on the appeals court circuit for two years, and has a limited "paper trail" of opinions on the issues that shape American society.
So when he is examined by the Senate Judiciary Committee, it is likely he will be pressed hard for his personal views on divisive areas like abortion, gay rights and medical research.
As news of his nomination broke, rights groups alleged he was hostile to women's reproductive freedom, citing a brief he co-wrote in 1990 on the Roe V Wade case that enshrined a woman's right to choose.
"The court's conclusion in Roe that there is a fundamental right to an abortion... finds no support in the text, structure or history
of the Constitution," it stated.
The brief was not a personal opinion, but was written while Mr Roberts was working for George Bush senior.
'Flips the court'
Judges are appointed for life, and the nomination of 50-year-old Mr Roberts gives President Bush the chance to expand his conservative agenda and extend it for many years.
SUPREME COURT HISTORY
1987: Democrats derail Reagan's Supreme Court nominee Robert H
1991: Last contested nomination involved Clarence Thomas who
narrowly won confirmation
1994: The last high-court vacancy
Political analyst Professor Stephen Hess, of George Washington University, says Mr Bush has made "a brilliant appointment" in political terms.
"The president gets his conservative and flips the court," he told the BBC.
"But it is also someone well-known and well-liked who could glide through the confirmation.
"We may well see as easy a process as it is possible to have at a time when before the announcement, both sides were preparing for war over this."
However Democrat Senator Charles Schumer, on the judiciary committee, sounded a note of caution.
"It is vital that Judge Roberts answer a wide range of questions openly, honestly, and fully in the coming months," he said.
"His views will affect a generation of Americans and it is his obligation during the nomination process to let the American people know those views."
This is the first Supreme Court nomination process in the era of 24-hour cable news networks and the internet.
It also comes at a time of enormous polarisation between Republicans and
Democrats, but in particular between conservative and liberal America.
Interest groups from across the political spectrum have raised millions of dollars to fund election-style campaigns supporting or attacking the nomination - which are already swinging into action.
The prime time scheduling of Mr Bush's address to the nation, in which he appeared alongside Mr Roberts, suggested the White House was seeking maximum impact for the news.
It was a sign of the great importance the president has placed on the decision - and it also gave him the chance to get onto the offensive early.
He could not have picked a better way of removing from the headlines the embarrassing story about his closest aide Karl Rove, who has been implicated in the row over the leaking of a CIA agent's name.
With the Supreme Court set to dominate the news agenda, leading Democrats are irked that they are losing a chance to make the most of the president's discomfort.