All Kinds of Primaries

It's worth recalling that the presidential primary isn't the only primary on the calendar this year. Maryland voters will, for example, seen be choosing between business Democrat incumbent Al Wynn and his challenger, Donna Edwards, backed by a "vast left-wing conspiracy" of progressive allies.

These sorts of challenges are, in my view, extraordinarily important. Having a left-wing challenger beat just one incumbent Democrat would have an enormous exemplary effect on the others.