John McCain has won in these blue core Democratic states:
California
Connecticut
Delaware
District of Columbia
Illinois
Maryland
New Jersey
New York
Rhode Island
Vermont
Washington
Wisconsin
John McCain has won in these big swing states:
Arizona
Florida
Missouri
Ohio
Virginia
John McCain is the candidate who has won the most core blue Democratic states and who has won the most big swing states. Clearly, then, John McCain is the best candidate to beat John McCain.