MoJ: McConnell: "Is There Still a 'Catholic Question' in America?"

"The important question facing the nation was not whether forty million Americans baptized into a certain religion are excluded from the presidency, but whether many more millions of Americans are excluded from full political participation because they ground their understanding of justice and morality in the teachings of their faith."

What does he mean by this? I don't think I'll trudge through the whole speech to find out; it seems like he is tackling the political problem from the wrong premises.