This post by Jed Babbin at Human Events puts it well.
The real operative part of the column is about what McCain must do tomorrow at the Conservative Political Action Committee conference. Word has it that McCain wants to have an old video of Reagan to introduce him:
First, he could throw away the Reagan video introduction. If he uses it at CPAC -- a house that Reagan built -- he could alienate a large portion of the conservatives he needs.
Second, he could say a lot more than he has so far on three key issues: Supreme Court appointments, the war and illegal immigration.
By January 2009, more than half of the Supreme Court justices will be over the age of 70. It’s likely that the next president will have four or five nominations, especially if he (or she) is a two-term president. After the reports of McCain’s dismissive remarks about the conservatism of Supreme Court Justice Sam Alito (reported last week by Bob Novak and John Fund) McCain must convince conservatives that the justices he would try to appoint would be of the same judicial temperament as Chief Justice John Roberts and Justice Samuel Alito. McCain must say clearly and concisely that he would only appoint justices whose views are strict constructionist and that he would fight to get them through a Democrat-dominated Senate.
On the war, McCain needs to say more than just repeat his commitment to the troop surge. The surge is already ending and by late spring, most of the combat power committed to the surge will have to be withdrawn because we lack the troop strength to sustain it. What comes next is vital to success, and McCain needs to describe what he intends to do. He needs to say something like what Rudy Giuliani said throughout his aborted campaign: that America will remain on offense against terrorists and the nations that support them.
Third, and most importantly to many conservatives, McCain must argue convincingly that he really did learn the lessons conservatives taught him at great pains to both sides. He has said that he knows border security must come first, but his answers to questions both on Meet the Press and in the CNN debate before the Florida primary were evasive. Will he sign legislation that establishes a path to citizenship for the 12 to 20 million illegals already here? If he doesn’t commit to rejecting that idea, he will not win over the conservative community he needs to win in November.