Why can't one party campaign like the rules were written down beforehand, instead of hanging out running up the score in California? Getting rid of the elector

Why can't one party campaign like the rules were written down beforehand, instead of hanging out running up the score in California? Getting rid of the electoral college won't necessarily make Hilary win this time around. It will be a different vote entirely. Republicans will actually contest California and some others. They'll try to run up the score in Texas. They'll shift a couple issues left. The only sure thing from this change would be ignoring the spread out population.