Bush to Announce Supreme Court Pick Tonight

Update: ABCnews.com has a breaking news tag right now that says that a source has told them that Edith Clement is not Bush's pick. Isn't this fun? Also, what kind of news report is that? A "source" tells them? I know it's just a tag, and not a full story, but couldn't they give a little more info, like "White House source" or "court source" or "friend of a friend's cousin who works at the restaurant where the judge always has lunch?"
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Original post:

Everyone is reporting that President Bush will announce his nominee to replace Sandra Day O'Connor on the Supreme Court tonight in a prime-time address. The rumor is that he has selected Judge Edith Brown Clement of the U.S. Court of Appeals for the 5th Circuit. I don't know much about her, although I do know how to pronounce her name, thanks to this helpful link I found on Slate. As a side note, what is the deal with the President asking the TV networks to pre-empt primetime programming so he can make his announcement? Isn't it more standard procedure to just make the announcement in a morning or afternoon Rose Garden address?