The chart below shows John McCain's two party vote margin for all fifty states and DC in the 2008 general election. The independently allocated Congressional districts of Maine and Nebraska are depicted in addition to the whole state results.
The next chart shows just the states that McCain won, in decreasing order of two party vote margin, with the cumulative electoral vote haul graphed left to right. Electoral vote quantities represent 2012 values adjusted after the 2010 census (McCain actually won 173 electoral votes).
The third chart shows Romney's performance if he is able to increase the Republican vote to about 50.9%, just enough to capture Colorado and therefore electoral majority. Again, only states he wins are shown, and the cumulative electoral vote total is given.