New York was generous Tuesday to its native son Donald Trump. He grabbed 89 of the 95 delegates up for grabs and for the first time in any state received more than 50% of the vote.

Mr. Trump’s sweeping victory was impressive. But, as Henry Olsen of the Ethics and Public Policy Center pointed out at National Review, it was also expected. New York Republicans tend to be self-described moderates, and either unchurched or Catholic—all groups that Mr. Trump has dominated in other states. Those demographic factors, combined with...