Harriet Miers, President Bush’s nominee to replace Supreme Court Justice Sandra Day O’Connor, could be moving from the minor leagues to Game 1 of the World Series.

Miers has never been a judge, putting in question her qualifications for filling the last vacancy in the Supreme Court. But little is known about her, and the president has simply asked that Congress trust him on this one, promising he has “picked the best person [he] could find.” Bush must know something nobody else does.

The president himself has described Miers as a “pit bull in a size 6 shoe,” noting her service as Bush’s counsel since his first campaign for Texas governor in 1993 as a time during which she has made obvious her enthusiasm for hard work.

If confirmed, Miers would be the first justice with no previous experience on the bench since former Chief Justice William Rehnquist. And unless Congress digs deeper into her background, they would be taking on quite a gamble.

Speculation has arisen that Miers is a strong advocate against abortion, especially when she worked in her home state of Texas, where she first became acquainted with the Bush family.

Though never a judge, Miers has served as president of the Dallas Bar Association in the 1980s, then successfully ran for City Council for a short-lived two-year term. Just before moving to the White House, Miers was briefly president of the Texas Bar Association.

The close resemblance between Miers and the justice she would replace are sometimes even shocking: both were at the top of their graduating class in Texas, both had trouble finding their first jobs, and then both were elected to city council. Now both have undoubtedly made history.

Bush’s nomination shows he is not trying to play political games to make sure the Supreme Court returns to the conservatism it had during Rehnquist’s reign as Chief Justice. But the newly nominated Miers is still largely a mystery, and Congress should make sure this last piece to the puzzle is the right fit.