“In the 2012 campaign every candidate for the Republican nomination has invoked Reagan and compared him or herself to Reagan. I don’t blame them a bit,” said Mr. Barbour. “But let me make sure that one thing is clear about Ronald Reagan’s Republican Party: Reagan did not demand or expect everyone to agree with him on every issue. He wasn’t a purist.”

“Some candidates are vying to be the most conservative candidate, and some voters are seeking purity in their choice,” he added. “Well, in politics purity is a dead-dog loser. You need unity. And purity is the enemy of unity.”…

“Ronald Reagan had an ideology, a strong philosophy with matching principles,” Mr. Barbour said. “But he was not an ideologue. He didn’t let the perfect be the enemy of the good.”