The Dwindling Centrist Democrat      

That’s the number of Democrats in the House of Representatives who have decided not to run for reelection in November’s midterms or are seeking another public office. That’s double the number of House Republicans who have also given voters their notice.

The party out of power — in this case the Republicans — traditionally gains ground in midterms. Since the Democrats are losing more incumbents, they will have an even harder time retaining their already slim control of Congress.

The bigger story in the current spate of retirements is that half of the Democratic dropouts belong to the “Blue Dog” coalition of centrist Democrats, now a dying breed in Washington.

Some were pushed out because they realized they could not compete in newly redrawn districts that favor Republicans. But most are quitting because of the mounting challenges they face from progressive Democrats, the new wunderkinds of American politics.