Mostly he is remembered in Catholic circles for his "separation of church and state" campaign speech to a group of Protestant ministers in Houston. Apparently he convinced them. It only proved to Catholics that he had phenomenal diplomacy. One man wrote his remembrance of the speech by saying: "He stared down the anti-Catholic know-nothings and won the hearts and minds of more than a few WASP and Jewish voters, as well as the admiration of Roman Catholics whose ancestors did not hail from the Emerald Isle."
And if so (gasp), what would any Pope have said: Stand opposed to artificial contraception since it is un-Biblical? (Pope Paul VI actually said The Pill was wrong anyway, in 1968.) Stand against abortion? Stand up for traditional marriage? Stand for equal rights regardless of race or creed?
How is it then that a Catholic platform would be bad policy for America? It's ironic that Catholics and Protestants stand together today for these same principles and value a "whole fabric of harmonious society."