NEW YORK - To win the presidency, Republican John McCain will continue stoking doubts about Barack Obama's tax policies and readiness to be commander in chief while hoping the volatile electoral map ultimately will look more or less as it did in 2004, when President Bush was narrowly re-elected.

   It's a daunting, perhaps insurmountable, challenge.

   With just over a week to go in a political climate that overwhelmingly favors Democratic nominee Barack Obama, McCain has increasingly limited options to reach the 270 Electoral College votes needed for victory. His state-by-state strategy allows him almost no margin for error.