SIMI VALLEY — Rudy Giuliani's withdrawal/endorsement statement, delivered here at the Reagan Library less than two hours before the final Republican debate, was both awkward and courageous.  Many candidates, of course, make the sudden transition from viable candidate to also-ran, but the ex-New York mayor's slide was particularly swift, and must strike even the jaded campaign observers here as a stunning study in contrast.  McCain looked confident and focused; Giuliani, standing a long step to his right, spoke with candor and some humor.  He said he would campaign for McCain in California, New York, New Jersey and Connecticut, but with Super Tuesday arriving in less than one week, and given Giuliani's surprising weakness in the primaries to date, there is perhaps more practical benefit from Giuliani's withdrawal than from his active campaigning.  McCain, like Romney, will be scraping for every vote in the next week, and Giuliani's supporters, donors included, are now free to move to McCain, the remaining candidate closest to the views and values of the man once known as “America's Mayor.”