It's disturbing to hear some conservative leaders cite Harriet Miers' religious faith among the qualities that make her a wise nomination to the Supreme Court.

And now the president himself has alluded to Miers' evangelical Christianity as a factor in the selection. This week Bush was asked why, over the past several days, White House advisers pointed to Miers' Christian belief system to defend her nomination to religious leaders such as James Dobson of the conservative Christian organization Focus on the Family.

His answer was that people "want to know Harriet Miers' background ... and part of Harriet Miers' life is her religion."

There. It's out now. White House handlers now may be trying to repackage that statement, but it seems clear that religion has been made an issue in this debate.

What's especially distressing is that Bush appears to be applying a separate standard in this case. Before nominee John Roberts stepped into the U.S. Senate hot seat a few short weeks ago, the president insisted that Roberts' Catholic background not become an element in the questioning.

And he was right. Religion should remain a private matter, and Bush's objection was sensible. Where has that good sense gone now?

Miers' critics on the left now charge that religion is being used as a "code" that suggests she will vote according to her private beliefs. That fear may or may not have a valid basis. Miers has never been a judge, so it's unknown to even her close friends how she will function as one.

The nominee herself can't even know, because she hasn't tried; applying logic and reason in a judicial sense is a wholly separate discipline from the practice of corporate law she has pursued in the course of her career.

Senators should evaluate Miers' principally on her qualifications, experience and how she defines her judicial role.

But now that the conservatives have made religion an issue, they can't rightfully stop senators from asking her whether she might bring her religion to her work.