If there is one bright star in the bleak congressional landscape, it is Justin Amash, the Republican congressman from my home state of Michigan, who was just re-elected for his fifth term. At a time when almost every other GOP politico has flipped and flopped on Trump, depending on whether his/her political ambitions are served by cheerleading or resisting him, Amash has been a lonely voice of sweet reason. He has unwaveringly stood up to Trump not to score points or advance his career—or his stock among liberals—but for the sake of a principled libertarianism anchored in limited government, markets, fiscal responsibility, pluralism, tolerance, and a humane and pro-growth immigration policy.

So it is very disappointing that he commented this week to the Ionia Sentinel-Standard that he does not have an "inherent" problem with a border wall to control illegal immigration. This shows just how much Trump's presidency has moved the Overton Window on immigration in general and the wall in particular.

That Sen. Lindsey Graham (R–S.C.), who called Trump "a race-baiting, xenophobic, religious bigot" who "doesn't represent my party" after Trump proposed his Muslim ban, should now be four square behind the wall is one thing. Graham pulled a Trump Tower–sized switcheroo last year when his poll numbers in South Carolina tanked and it became clear that his #NeverTrump stance might cost him his re-election bid. At that point, he started shooting little Twitter valentines to Trump declaring that the Donald is "just what America needs" because he "relishes being the Law and Order president and a strong Commander in Chief."

Mitt Romney, the incoming freshman senator from Utah, has pulled another switcheroo of his own. After accepting Trump's endorsement twice—once before his failed presidential run and then for his Senate bid in the fall—Romney penned a scathing op-ed this week denouncing Trump as "divisive, racist, sexist, anti-immigrant, dishonest or destructive to democratic institutions." No doubt, Romney is trying to replace outgoing Sen. Jeff Flake as the Senate GOP's leading anti-Trumper (which would be a worthy goal, except that Romney is no Flake). He too has said he'd vote for Trump's wall, a position that represents a small glimmer of consistency in Romney, actually, given that he was way ahead of the curve in staking a harsh restrictionist position: Running for president in 2012, he declared that he wanted to push illegal aliens to "self deport"—a position that Trump at the time called "maniacal" and blamed for Romney's loss.

In contrast to Graham and Romney's opportunism, Amash has been a sincere and steadfast voice of opposition, a man who consults not his political interests but his bedrock commitments when he opines on Trump's policies and antics. He has supported Trump's criminal justice reforms and the few other good things the president has done. But he has also gone after Trump in no uncertain terms for bad-mouthing minorities and immigrants, and for proposing to get rid of birthright citizenship by executive order, and for waxing rhapsodic about his "easy to win" trade wars, and for mocking Rep. Mark Sanford for losing the election.

Amash has also called out other Republicans—including fellow members of the misnamed Freedom Caucus—as they've drifted toward Trumpism, trading their commitment to limited government and fiscal responsibility for a protectionist, reactionary nationalism. Amash was the only Republican who opposed the House GOP's resolution last summer "supporting the officers and personnel" of ICE, a bill whose sole purpose was to embarrass the anti-ICE left. In a tweet, Amash denounced as "dubious" the resolution's claim that ending ICE would allow gangs to roam free. He asked why his party would "treat a federal agency as though it's beyond reproach and reform."

So again, it's troubling that Amash of all people would now be saying that if the wall is "done thoughtfully," after taking into "consideration private property at the border and environmental concerns," he'd be "OK with it."

Walls are the specialty of Communist regimes that regard the outside world as a threat to their control. A wall with Mexico, a friendly neighbor, would be particularly terrible, because it would cut across an area that has historically been integrated around geographic, economic, cultural, and even ethnic lines. Indeed, the border in towns like Laredo, Texas, literally runs through families, with one half living in America and the other half in Mexico. Even mortal enemies like India and Pakistan have not erected artificial physical barriers between them, holding out hope that one day they will bury the hatchet and be united in trade and friendship.

Setting that aside, there are also many practical reasons why the wall would be "inherently" bad and not "OK."

For starters, as Nick Gillespie and I (and numerous other Reason writers) have pointed out repeatedly, notwithstanding the hysteria about migrant caravans, border apprehensions are at a historic low; the number of Mexicans entering the country without authorization has plummeted, due to entirely natural causes. And it is unlikely to pick up again, because Mexico, like the rest of the world outside Sub-Saharan Africa, has completed its "demographic transition"—meaning its fertility rate has dropped as more infants survive to adulthood—so it no longer has surplus young men to send our way. Indeed, right now there are more Mexicans leaving America than entering. Even if you see immigration as a battle, building a wall would be fighting the last war.

Furthermore, at least half of the unauthorized population consists not of border jumpers but visa overstays (a non-trivial number of who at any given time are illegal because America's Kafkaesque immigration bureaucracy failed to renew their visas in a timely fashion). A wall will do nothing about that. And the profits for drug smugglers are too huge to be deterred by a wall, as the Bipartisan Institute's Theresa Brown has argued. Nor will it thwart motivated terrorists. The best way to enhance border security is not a silly wall; it's to give those who mean no harm legal avenues, such as guest worker visas, to come to America. This will reduce cross-border illegal flows even more, handing America far more operational control over the border far more cheaply.

There is an argument, as I said last week, for paying Trump some ransom money for his wall in exchange for legalizing DREAMers (those who were brought to the country without authorization as minors) and Temporary Protected Status holders (those trying to escape turmoil or violence in their native countries). This is especially true since he has dropped his asking price considerably since the last shutdown. At that time he was demanding $25 billion and a 40 percent cut in legal immigration. This time, he wants "only" $5 billion.

But just because it is sometimes necessary to pay ransom to avoid a bigger catastrophe doesn't mean it is "inherently" OK, no matter how small the amount.

That Amash, the man with the strongest moral compass in the GOP, should be signing off on a wall rather than calling for a guest worker program shows just how much the conversation about immigration policy has deteriorated in the GOP, compared to the 1980s when such sentiment was conventional wisdom in the party and the country.

Indeed, watch this 1980 debate between George H.W. Bush and Ronald Reagan and weep.

When asked whether kids of illegal aliens should he allowed a free education in public schools, Bush argues "yes." It would do no good to anyone to deny them an education, he says. Then he goes on to point out that the only reason that substantial illegal immigration even exists is because America has made certain forms of labor that should be "legal" "illegal," turning a whole bunch of "honorable, decent, family-loving people" who are "good" and "decent" and "part of my family" into law breakers.

Reagan one-ups Bush and says that "barriers" are not the answer to dealing with all the unemployed youth in Mexico at that time who wanted to come to America to work. "Open the border both ways," he declares, calling specifically for "work permits" so that Mexicans can "come and go" legally from America. He points out that the fact that Mexicans can come to America to work is a "safety valve" that "prevents the lid from blowing off down there" and calls for working with Mexico in a "mutual recognition" of our common problems. No idiotic demands that Mexico pay for a wall. No denouncing it for sending "rapists" and "criminals" and not its "best people."

Sad!