Ilya Somin at Volokh – Causes of the Defeat of Proposition 98
There were two major causes of Prop 98’s defeat. One was the sponsors’ mistake in combining the popular cause of restricting eminent domain with a far less popular phaseout of rent control.
The second and more unusual cause of 98’s defeat was the presence of Proposition 99 on the ballot.
If you are interested in this, please check out Ilya Somin’s extensive writings on Proposition 98 and 99 at The Volokh Conspiracy.