The problem is that Specter has a track record of dishonesty on Supreme Court nominations. He flat-out LIED about Bork and the nature of his contacts and talks with Bork.
If he is seated as committee chair (or on any committee), it must be done on a conditional basis. If he gets out of line, he needs to be automatically booted from all committee seats.
Being chairman of the committee is a position of special trust and honor. He hasn't satisfied me that he actually deserves said trust and honor.
When he is seated it will be because he has satisfied the Senate.