I recently was asked by someone whether laws such as Oregon's "double
majority" tax requirement--basically a quorum requirement on ballot
measures which specifies that in order for voters to alter taxes, at
least 50% of registered voters must cast ballots, and then at least 50%
of the voters must approve the proposal--violates the federal
constitution.  On its face, I cannot see a credible equal protection
argument here; is anyone familiar with any litigation relating to quorum
requirements on ballot measures as opposed to legislative bodies?

Thanks,
Todd Lochner
Boise State University