As populations become more urban and the politics more evenly divided (which is a great gain in California, where they had not been divided for at least a decade), this tactic becomes more and more critical to victory. When you can get 55% of the Independents (a polar swing in California, where prior to yesterday the Indies were 55-45 the other way for a decade) and take 18% of your opposition's vote from him, you simply cannot lose.
In many states of the south or great plains or mountain west, such strategies as this are not necessary. In the more urbanized states of the east, Great Lakes and on the very wacky west coast, this is how you win.
Now Arnold must cut some unpopular taxes and relieve some unpopular business burdens to seal the deal in California. And it wouldn't be too terribly surprising to see the voters in Washington and Oregon take notice if California gets its act together. These two other west coast states are only a half-step behind California on the path to the big cliff.