...Last Tuesday was primary day in Arizona and Nevada, and we think the results deserve a little more national publicity because they revealed some useful political lessons. To wit: immigration doesn't win elections but the tax issue does. Two Arizona incumbents, Republicans Jim Kolbe and Jeff Flake, faced primary challenges resulting from their position on immigration. Both back sensible reform of our immigration system. Both support President Bush's call for a guest-worker program to match willing foreign workers with U.S. employers and draw illegal aliens out of the dangerous underground economy. And as a result of these views, Messrs. Kolbe...