Moderate Republicans are, were, good things. I use the past tense “were” because as they became rarities, the centrists’ chief function was preserving majorities in Congress for their radicalized party. …

There arose the stupid “RINO (Republican in name only) Hunters Club,” courtesy of the National Federation of Republican Assemblies. In 2005, Rush Limbaugh pounded away at Republican “traitors” in the Senate, adding that “they all happen to be from the Northeast, and they all happen to be moderates. They all happen to be liberals.”

And now they all happen to be gone, except for a few exceptions. Thus, the Senate has a Democratic majority.

Defenders of the older, more marketable Republican brand are trying to curb the party’s more feverish elements. In 2012, the enraged ones purged Sen. Richard Lugar of Indiana, a revered statesman virtually assured of winning the general election. Instead, they chose a nominee expounding bizarrely on rape, and he lost to Democrat Joe Donnelly. And in 2010, similarly flawed Republican candidates saved the hides of Senate Majority Leader Harry Reid in Nevada and Sen. Michael Bennet in Colorado.