By Matthew Davis
BBC News, Washington
There has been a collective scratching of heads on Capitol Hill at President George Bush's decision to nominate a member of his inner circle with no experience of being a judge to fill the vacancy on the US Supreme Court.
Harriet Miers would be the third woman to serve on the high court
Harriet Miers, 60, is a long-time confidante of the president who is described as a trailblazer for women and who has held a variety of impressive posts.
But politicians from both sides of the political divide are concerned about a candidate with no public profile whose views are unknown on the contentious issues that the court deals with, like abortion and gay rights.
Ms Miers would replace Justice Sandra Day O'Connor - the holder of a key swing vote on the bench - and her nomination augurs for a fierce confirmation hearing.
HARRIET MIERS' CAREER PATH
1985: First female president of the Dallas Bar Association
1992: First woman to head the Texas State Bar
1995-2000: Chairwoman of the Texas Lottery Commission
2001: Joins White House staff as president's staff secretary
2003: Appointed Deputy Chief of Staff
2004: Named White House counsel
Even less is known about her opinions than those of John Roberts, the new chief justice who skilfully dodged questions over how he would rule on contentious cases when he testified before the Senate earlier this month.
Leading Democrats say they will put pressure on the new nominee to answer questions about her judicial philosophy and legal background before any vote.
But Ms Miers is also something of an unknown quantity to Republican lawmakers.
Senator Sam Brownback of Kansas - a conservative - has said he would vote against a nominee who was not "solid and known" on cultural issues like abortion, same-sex marriage and religion in public life.
Yet in some ways the president's decision should not be a surprise at all as he has a track record of rewarding the loyalty of his inner circle.
Ms Miers was the president's lawyer in Texas, and he has given her a string of jobs since - from the head of Texas Lottery Commission, to his Deputy Chief of Staff and now White House counsel.
She is a trusted adviser with a reputation for discretion, essential in someone who vets all the papers that come across the president's White House desk.
Mr Bush could have picked a hardcore conservative in an attempt to reach out to core supporters at a time when his national approval ratings are at record lows, and the Republican Party itself is reeling from scandals surrounding two of its leading members.
Yet he appears to have reached out to the middle ground - by picking a woman to replace a woman - and by consulting with Democrats, some of whom suggested her as a potential candidate.
Ms Miers is an unusual Supreme Court nominee in that she is the first for more than 30 years not to have
been a judge.
One administration official said some senators from both parties thought it was important for Bush
to "think outside the Appeals Court" by picking someone who could offer a different perspective on the job.
Another unusual aspect of Ms Miers nomination is that her office has led the vetting and
recommendation of candidates for the Supreme Court vacancy.
Mr Bush reportedly organised a private consultation on Ms Miers suitability for the position and
offered her the opportunity over dinner at the White House on Sunday evening.
The president seemed to try to answer any critics by emphasizing Ms Miers' legal successes in what some commentators saw as a defensive announcement of her nomination.