There is an argument which I will mention. If the President failed to make a timely nomination, since the text of the Constitution says 'he shall nominate', then, in theory, he could be impeached for failure to perform a constitutional requirement. Of course, that will not happen. If they hated him enough to want to remove him, they would use a more powerful argument.
He need merely nominate someone qualified. If Congress fails to confirm - well - that is their affair.