Donald Trump wears his character flaws on his sleeve. Hillary Clinton seeks to prevent documentation of hers, even when the law requires it. Yet despite her best efforts, facts about Mrs. Clinton that are now public should trouble voters more than any of Mr. Trump’s remarks.

Not that it’s easy for Republicans to appear on a ballot with Mr. Trump, especially since media folk spend days after each controversial remark demanding responses from other GOP candidates. The objective is to force them to endorse or condemn Mr. Trump...