Some things are right even if Donald Trump believes them. The President’s Constitution Day speech was a doughty defence of America from the slanders of its enemies domestic, but it was also an uncanny, if wholly inadvertent, defence of liberalism. Uncanny because liberals have waited a long time to hear a senior liberal politician demur from the ascendant anti-liberalism, let alone challenge its ideology head-on, and yet the dissent is being led by an anti-liberal of a different stripe.