Once upon a time there were independent and moderate Republicans in this country. Think, among others, Nelson Rockefeller and William Scranton. And don’t overlook the likes of Iowa’s Robert Ray, who governed from 1969 to 1983 by appealing across party lines to independents, to Democrats and to fellow moderates in his own Republican party. Bob Ray is so popular still that they name city streets after him in hometown Des Moines.

Instead of following Ray’s recipe for success, Republican politicians nowadays appear to believe the more polarizing the better. Iowa’s GOP is no exception. Following Ray’s 14 years in office his party veered sharply to the right, adopting extremist party platforms and making pariahs of longtime moderates.

Mary Louise Smith, a pro-choice feminist and Ray ally, was national GOP chairwoman from September 1974 until January 1977 but 20 years later the Iowa party had become so intolerant and rightist it humiliated her by not even allowing her on the floor of the national convention in her own name; Smith could access the floor only after borrowing an usher’s credentials.

Bob Ray’s brand of moderation is hard to find anywhere in GOP ranks nowadays. He fought the death penalty. He brought Asian immigrants to Iowa and made them feel welcome. In shunning those sorts of humane, moderate policies, Republicans have adopted a kind of isolationism from points of view they don’t find congenial. If politicians have a hint of moderation in their history, they do their best to walk away from it. Call it the new isolationism.

In the past, Republicans boasted how they welcomed diverse viewpoints into their “big tent.” Now the home for their moderates-need-not-apply party looks more like a pup tent.