From syndicated columnist Ruben Navarrette Jr.:

The truth is that Democrats want to make an example of Miguel Estrada,
whose appointment to the bench could make Hispanic voters look more
favorably on the Bush administration. They also want to send a message to
the White House that when it comes to confirming federal judges, there are
some things they simply will not tolerate. Apparently at the top of the
list: Independent-minded Hispanic hotshots who don’t go around thanking
liberals for everything that the nominees have accomplished on their own.