House Speaker Paul Ryan at a Capitol Hill news conference last week marking the six-month anniversary of the tax reform bill. (The Minnesota Star Tribune)

Amid the carnage of Republican misrule in Washington, there is this glimmer of good news: The family-shredding policy along the southern border, which was merely the most telegenic recent example of misrule, clarified something. Occurring less than 140 days before elections that can reshape Congress, the policy has given independents and temperate Republicans — these are probably expanding and contracting cohorts, respectively — fresh if redundant evidence for the principle by which they should vote.

The principle is: The congressional Republican caucuses must be substantially reduced. So substantially that their remnants, reduced to minorities, will be stripped of the Constitution's Article I powers that they have been too invertebrate to use against the current wielder of Article II powers. They will then have leisure time to wonder why they worked so hard to achieve membership in a legislature whose unexercised muscles have atrophied because of people like them.

Consider the melancholy example of House Speaker Paul Ryan, who wagered his dignity on the patently false proposition that it is possible to have sustained transactions with today's president, this Vesuvius of mendacities, without being degraded. In Robert Bolt's play "A Man for All Seasons," Thomas More, having angered Henry VIII, is on trial for his life. When Richard Rich, whom More had once mentored, commits perjury against More in exchange for the office of attorney general for Wales, More says: "Why, Richard, it profits a man nothing to give his soul for the whole world ... But for Wales!" Ryan traded his political soul for ... a tax cut. He who formerly spoke truths about the accelerating crisis of the entitlement system lost everything in the service of a president pledged to preserve the unsustainable status quo.

Ryan and many other Republicans have become the president's poodles, not because James Madison's system has failed but because today's abject careerists have failed to be worthy of it. As Madison explained it in Federalist 51: "Ambition must be made to counteract ambition. The interest of the man must be connected with the constitutional rights of the place." Congressional Republicans (congressional Democrats are equally supine toward Democratic presidents) have no higher ambition than to placate this president. By leaving dormant the powers inherent in their institution, they vitiate the Constitution's vital principle, the separation of powers.

Recently Sen. Bob Corker, the Tennessee Republican who is retiring, became an exception that illuminates the depressing rule. He proposed a measure by which Congress could retrieve a small portion of the policymaking power that it has, over many decades and under both parties, improvidently delegated to presidents. Congress has done this out of sloth and timidity — to duck hard work and risky choices. Corker's measure would have required Congress to vote to approve any trade restrictions imposed in the name of "national security." All Senate Republicans worthy of the conservative label that all Senate Republicans flaunt would privately admit that this is conducive to sound governance and true to the Constitution's structure. But the Senate would not vote on it — would not allow it to become just the second amendment voted on this year.

This is because the amendment would have peeved the easily peeved president. The Republican-controlled Congress, which waited for Trump to undo by unilateral decree the border folly they could have prevented by actually legislating, is an advertisement for the unimportance of Republican control.

The Trump whisperer regarding immigration is Stephen Miller, 32, whose ascent to eminence began when he became the Savonarola of Santa Monica High School. Corey Lewandowski, a Trump campaign official who fell from the king's grace but is crawling back (he works for Mike Pence's political action committee), recently responded on Fox News to the story of a 10-year-old girl with Down syndrome taken from her parents at the border. Lewandowski replied: "Wah, wah." Meaningless noise is this administration's appropriate libretto because, just as a magnet attracts iron filings, Trump attracts, and is attracted to, louts.

In today's GOP, which is the president's plaything, he is the mainstream. So, to vote against his party's cowering congressional caucuses is to affirm the nation's honor while quarantining him. A Democratic-controlled Congress would be a basket of deplorables, but there would be enough Republicans to gum up the Senate's machinery, keeping the institution as peripheral as it has been under their control, and asphyxiating mischief from a Democratic House. And to those who say, "But the judges, the judges!" the answer is: Article III institutions are not more important than those of Articles I and II combined.

George Will is at georgewill@washpost.com. His column is distributed by the Washington Post Writers Group.