Those who read this space know I am not a fan of the Republicans’ vaunted “Pledge to America.” I’m for simple pledges, the kind that get back to basics. If the Republican party is interested in making a pledge like that — a pledge that will resonate with the vast majority of the American people — here’s a suggestion: Promise an unwavering commitment to the principle of equal protection of the law for every American citizen. Promise, therefore, that Congress will investigate weighty allegations that the Obama Justice Department is engaged in racist law-enforcement practices. Promise, moreover, that any executive-branch...