Let's look at the merits of the O'Connor nomination to succeed herself:
- She's female.
- She's fairly conservative, but within the mainstream, and thus at least marginally acceptable to a broad spectrum of political factions.
- She's from the West, preserving some geographic diversity on the Court.
- She's not from the Ivy League.
On the other hand, there are some drawbacks:
- She's said she doesn't want the job any more.
- John McCain is also from Arizona, and Bush doesn't want to give him any appearance of support. After all, McCain opposes wholesome, all-American torture of detainees.
- While she did vote for him in the Presidential election of 2000-12-12, her personal loyalty to the alleged President isn't a given in the future.
On the whole, nominating Sandra Day O'Connor to the vacancy created by her own retirement wasn't the worst decision Bush could've made — after all, he could've appointed a completely unqualified crony or something — but I would say her chances of confirmation in the Senate don't look good.