From a cursory glance, David F. Hamilton seems like a perfectly fine moderate nomination to the appeals court. But, should a Supreme Court vacancy come up - which is more likely than not to happen a few times over the next 8 years - you must nominate a competent, well qualified liberal to the bench. We have to live for likely several decades with the George W. Bush picks of John Roberts and Samuel Alito, and anything less than an ideological counterweight to those two would be an extraordinary mess.
Now, considering President Obama's experience with constitutional law and my overall regard for him, I think he'll easily do the right thing. But I just wanted to have this down somewhere on electrons.