Mickey Kaus, author of “The End of Equality,” writes at kausfiles.com.

Who wants to deport "dreamers"? Not many people, it turns out. Even veteran immigration restrictionists seem willing to legalize this subset of undocumented immigrants if it is part of a package deal. That's true even though a lot of what's said about the dreamers is PR-style hooey.

For example, it's often said — indeed, former president Barack Obama just recently said — that the approximately 690,000 dreamers were "brought to this country by their parents." Well, many were. But that's not required to qualify as a protected dreamer under the various plans, including Obama's. You just have to have entered the country illegally before age 16. You could have decided to sneak in against your parents' wishes. You're still a dreamer!

Likewise, we’re told dreamers are college-bound high school grads or military personnel. That’s an exaggeration. All that’s actually required is that the dreamer enroll in a high school course or an “alternative,” including online courses and English-as-a-second-language classes. Under Obama’s now-suspended program, you didn’t even have to stay enrolled.

Compared with the general population, dreamers are not especially highly skilled. A recent survey for several pro-dreamer groups, with participants recruited by those groups, found that while most dreamers are not in school, the vast majority work. But their median hourly wage is only $15.34, meaning that many are competing with hard-pressed lower-skilled Americans.

The dreamers you read about have typically been carefully selected for their appeal. They’re valedictorians. They’re first responders. They’re curing diseases. They root for the Yankees. They want to serve in the Army. If dreamers are the poster children for the much larger undocumented population, these are the poster children for the poster children.

Still, taking the dreamers as a whole, not just the dreamiest of them, they represent an appealing group of would-be citizens. So why not show compassion and legalize them? Because, as is often the case, the pursuit of pure compassion comes with harmful side effects.

First, it would create perverse incentives. Can you imagine a stronger incentive for illegal immigration than the idea that if you sneak into the country your kids will get to be U.S. citizens? Sure, the protections don't currently apply to recent entrants — under Obama's plan, you had to have come before 2007. But those dates can be changed — Obama himself tried to do it once. And the rationale for rewarding those who arrive when young — that they're here through "no fault of their own" and know only America, etc. — can apply on into the future, with no apparent stopping point. What about the poor kids who came in 2008? 2018? There's a reason no country has a rule that if you sneak in as a minor, you're a citizen. We'd be inviting the world.

Second, it would have knock-on effects. Under "chain migration" rules established in 1965 — ironically as a sop to conservatives, who foolishly thought that they'd boost European inflows — new citizens can bring in their siblings and adult children, who can bring in their siblings and in-laws, until whole villages have moved to the United States. That means today's 690,000 dreamers would quickly become millions of newcomers, who may well be low-skilled and who would almost certainly include the parents who brought them — the ones who, in theory, are at fault.

There are obvious, sensible ways to control these side effects. Pair any dreamer amnesty with a major upgrade to our system to prevent a new undocumented wave — such as a mandatory extension of E-Verify, the system that lets employers check on the legal status of hires. Curtail the right to bring in distant relatives. Sen. Tom Cotton (R-Ark.) has proposed such a compromise — and it would be easy to compromise on his compromise, say by cutting back on chain migration only by the number of people that the new Dream Act adds to the citizenry. The president could declare a one-time act of mercy for those who came here during the pre-Trump Era of Laxity, but make clear the game was changed for future entrants.

Why wouldn't Democrats jump at such a deal? For years they've been touting "comprehensive immigration reform," a mix of amnesty with stepped-up enforcement to prevent another undocumented surge. But the Dream Act is uncomprehensive. It's all amnesty, no prevention — let alone any compensating reduction in legal inflows. It's hard to avoid the thought that Democrats (and Republicans who support the Dream Act) aren't really interested in preventing illegal inflows. They're not inclined to take Cotton up on his deal because they don't think they have to.

If they win, we'll get the compassion without dealing with its consequences. That would be especially unfortunate given the signs that Trump's immigration crackdown, simply stepping up enforcement of current laws, is already helping to tighten the low end of the labor market and boost wages of low-skilled workers. News organizations are featuring stories from employers who aren't getting their usual supply of undocumented workers and are forced to take radical measures — such as raising wages. Proof of this connection, in the public mind, may be what terrifies the pro-immigration lobby the most.