Very simple. This "alleged" poll shows that McClintock could win IF Arnold was out of the picture...
Arnold is proven that he has a very good shot at winning even with McClintock, but it would be close. With McClintock out if the picture, it would be a cakewalk.
Come Nov '04, is it's Clark vs. Bush vs. Nader, and the poll was done Bush vs. Nader, Bush would win all 50 states in a landslide, maybe even D.C. Ok, maybe not DC... The facts are, Clark won't be dropping out, so comparing Bush to Nader is irrelevant.
Close win or cakewalk, a win is a win. Why wouldn't you prefer a close win by a conservative over a cakewalk by a liberal?
The bottom line: evidence suggests that a conservative can win in California in this particular election at this particular moment in time. That makes liberal Schwarzenegger the interloper. If any Republican candidate deserves the contempt of conservative voters, it is Schwarzenegger--not McClintock.