Georgia10, writing on the front page at Daily Kos, Has a few words to say about the idea that the "a President is entitled to his nominee." G10's take is that, while this might be true as a general principle, this President has forfeited that right by betraying the public's trust. I'd like to go a step further and say that it isn't a valid principle to begin with.
The Constitution gives the President the power to appoint certain upper positions in the executive branch and to appoint all federal judges. It gives the Senate the responsibility to "advise and consent" on these appointments, a phrase which has always meant that they examine the appointees and confirm or reject them. Every president wants to get his way on all of his appointments. Historically, the Senate has usually given Presidents most of their wishes, only occasionally balking at clearly bad appointments (most recently Harriet Meirs) or holding up certain appointments as bargaining chips in fights with the White House (as Jesse Helms did with Clinton's judicial appointments).
Occasionally an argument for maximum Presidential power shows up that runs: the Senate should approve all appointments, without exception, because the Constitution says "consent," not "consent or reject." This argument is too silly even to deserve repudiation.
The more common argument, the one Georgia10 is referring to, treats consent as a simple courtesy. G10 explains:
The premise stems from the notion that it is he who has a vested appointment power, and that the Senate should accord the President a high degree of deference when he makes he choice.
That is, the American people have chosen this person to make appointments and, except in extraordinary circumstances, the Senate should respect that decision even is they disagree with the choice. Since what constitutes "extraordinary circumstances" is a matter of personal interpretation, there will always be wide latitude for debate on appointments.
I think, however, that it is a mistake to treat all appointments as equal and entitled to the same degree of deference (whatever degree you think that is). I'll argue that judicial appointments deserve less deference than do Executive branch appointments. In fact, I'll go so far as to say that the Senate has a duty to subject judicial appointments to a tougher standard of approval.
The Executive branch is an organization with the President as its chief operational officer. The heads of the various departments answer to the President and represent the president to the professional staff in those departments. To a certain extent, we expect the executive branch to reflect the president's priorities and carry out his agenda. The only limitations on the president's power over the executive branch are the laws passed by the Legislative branch* and the professionalism and inertia of the tenured civil service.
For the Executive branch then, it's really just a matter of territorial respect to give the President whomever he wants. It's his branch, he should be allowed to run it however he wants, and the Senate should only interfere when he's about to do something disastrous. It's the same courtesy that I give to my neighbors; they can make their house and yard as ugly as they want and I should only interfere when they are doing something really stupid, like dropping a tree onto a power line or their garage.
What is different about Judicial appointments? Primarily, it is that they are lifetime appointments that have the potential to outlast the administration of single President or the reign of a single party. The Supreme Court, in particular, by deciding on constitutional issues, has an impact measured in decades. For this reason, Judicial appointments should be more of a collaborative process than Executive appointments.
Executive appointments can and should reflect the policies and agenda of the President. Judges should more neutral, reflecting a broader consensus of the legal thought of their time. Put crudely, if the Senate isn't turning down more appointments of judge than of department secretaries, they probably aren't doing their job.
* Just as an aside, this is the point at which the "Commander-in-Chief" and "unitary executive" arguments begin in determining whether Bush is bound by the laws of the republic when carrying out national security duties. The military is part of the Executive branch. The proponents of maximum Executive power say that the Legislature has no business telling the president what he do within his branch. They are, of course, wildly wrong.