“The pope is the true American leader,” Italian senator and former prime minister Matteo Renzi said April 20 on National Public Radio’s "On Point." “Not President Trump. President Trump is a nightmare.” Stumbling upon that clip without context might stop some in their tracks: Trump supporters because a foreign politician seemed to be gratuitously insulting their president; secular Americans recoiling at the implication that all should become Catholics, if we weren’t already.