DAVID MARCUS: MAGA voters trigger anti-incumbent earthquake, and it's little wonder why

Over the past several days, two Republican thorns in President Donald Trump’s side, in the form of Sen. Bill Cassidy, of Louisiana, and Rep. Thomas Massie, of Kentucky, have been ousted in their primaries by GOP voters and by very healthy margins. But this is about much more than Trump.

All over the country, the animating issue for most Republican voters I talk to is rather simple. They say, "We gave the party the House, the Senate, and The White House, so why can’t popular legislation like the Save America Act...