Professor Sandy Levinson has a very interesting, and possibly quite accurate, post up on Balkinization as to why Bush chose to nominate Samuel Alito, rather than other equally qualified jurists who probably would have been easier to confirm (emphasis mine):
This makes a lot of sense to me. Roe v. Wade, and even gay marriage, while important to many liberals and to cultural conservatives, have never struck me as things that Bush or Cheney really gave a crap about – they say the right words to keep the “base” happy, but ultimately, they don’t much care. What they DO care about is their own power. And, as Levinson points out in the rest of the post (you should read the whole thing), there are a lot of tremendously important cases on executive power coming down the pike in the next couple of years.
These will be some of the most interesting, and most important, confirmation hearings in years.