In his own mind, sure. And he does hold an influential role, but not the only influential role.
Whether WE like it or not, if Specter nixes a judicial nominee, that person WILL be defeated.
McLame, Chaffee, Warner, Collins and Snowe WILL join him.
Result: 49-51 against.
Only the earlier (apparent) "deal" by the President and Frist that kept him in charge of the judiciary committee has kept him on board. Now that Miers has been denied her "up-or-down" vote, he can justifiably make the case that a nominee is not necessarily entitled to a vote.
I wasn't really crazy about Miers, but denying her a vote was a disaster in the making for sometime in the future.