Campaign '08: Thanks to an opponent's tactical error, Sen. John McCain won the South Carolina primary. But he forgot one thing: The Democratic primary in South Carolina is this week.Had Mitt Romney not withdrawn from South Carolina, he might have drawn enough Republican votes away from McCain to give the contest to Mike Huckabee. McCain would have been reduced to a one-hit wonder facing a barrage of primaries where only registered Republicans could vote. Huckabee still would have faced state campaigns where evangelical is just a word in the dictionary, and not even the mainstream media, looking for a straw...