“Yes we can!” chanted visitors to the Senate Judiciary Committee hearing room when the final vote on comprehensive immigration reform of 13-5 was announced on Monday night.

Actually, we’d rather not.

Forget the particulars of the bill, which are, indeed, bad enough. It is the notion that a large dollop of American society can successfully be “reformed” by the stroke of a pen, with little consequence to this and future generations, that makes “comprehensive” legislation a symbol of bad and imprudent governance.

How bad and imprudent? The law of unintended consequences figures mightily into any comprehensive reform that seeks to predict what a particular situation will be like 5 or 10 years down the road. Anyone who doubts that need only look at Obamacare to realize that almost everything on which the administration sold comprehensive health care reform is falling apart. Also, most of the benefits promised not only will never be realized, but the bill will have created exactly the opposite of the effects intended. Costs of insurance will skyrocket, far fewer people will sign up for insurance via the exchanges than was imagined, and the legislation will have almost doubled in anticipated costs by 2020.

And yet, here we go again. “Comprehensive” immigration reform will hit the Senate floor, and the immigration system, groaning under the 800 pages already written with some promised amendments to come, could be entirely undone by the time the House and Senate are through with their “historic” reformation.

What is the impulse that drives politicians to eschew the common-sense idea of incrementalism — taking on problems piecemeal with carefully considered legislation dealing with one aspect of the question at a time?

Back in December, Jonathan Chait, writing in New York magazine, gave the classic liberal response to the idea of incrementalism as he skewered Senator Marco Rubio ‘s preferred approach to immigration reform:

On immigration, meanwhile, Rubio is carefully positioning himself to oppose any potential deal. He is not coming out and immediately throwing his body in front of the legislative train. Rather, he pleads that we must not try to do everything at once and should instead try to reform immigration “step by step.” Of course, “step by step” is exactly the catchphrase Republicans used to oppose health-care reform. It’s a way of associating yourself with the broadly popular goal of reform while giving yourself cover to oppose any particular bill that has a chance to pass. You’re not against reform, you’re against this reform. It’s too much, too fast.

What Chait failed to add was that incrementalism isn’t dramatic enough or historic enough. There’s no such thing as “too much, too fast.” At heart, liberals like Chait and Obama are drama queens because, let’s face it, it’s so boring to have to get in the trenches and do the scut work of democracy by carefully considering legislation and its consequences before moving on and facing the next challenge. You don’t make history that way, by George, and what’s the point of winning elections if you can’t go down in the history books?

An exaggeration, to be sure, because what the president and many Democrats will say is that it is good, simple, practical politics to wrap everything up in one gigantic package and try to ram it through Congress. It’s just easier to fix big problems this way and the incremental approach would never work because some of what they want would never pass unless there were sweeteners added to buy the votes of politicians not inclined to go along.

But should it be “easier” to try and reform one-sixth of the U.S. economy? Shouldn’t that be extraordinarily hard to accomplish? As hard as Democrats think it was to pass Obamacare — and it didn’t have to be that hard with their huge majority in the House and a filibuster-proof majority in the Senate — it evidently wasn’t hard enough. We will be living with the unintended consequences of the Affordable Care Act for many years to come unless it is repealed.

The fact that we don’t know what those exact consequences will be is reason enough to drop the idea of comprehensive reform of anything. The New America Foundation’s Michael Lind, writing in the Washington Post in 2010:

The second reason comprehensive reform is problematic is that it assumes an ability to foresee problems and fix them in advance — a skill not necessarily found among mere mortals. The longer the time horizon, the greater the hubris of those who claim to be solving problems not just for today but for generations to come.

This overconfidence spans the political spectrum. For example, both liberal environmentalists and conservative deficit hawks rely on sophisticated models to predict dire threats decades away, whether a catastrophic rise in the Earth’s temperature or unsustainable entitlement spending. In each case, even slight changes in the variables can make the remote future look either scary or benign. But when scholarship gives way to advocacy, possible problems generations out are often presented as all-but-certain disasters — avoidable only by immediate action.

The way to avoid this trap is by embracing the lost civic virtue of prudence. Jefferson wisely said, “The same prudence which in private life would forbid our paying our own money for unexplained projects, forbids it in the dispensation of the public moneys.” Jefferson was well aware that imprudence in the use of public monies led to unintended consequences — the bane of good governance. When an exasperated Nancy Pelosi told a reporter in a response to a question of what exactly was in the ACA that “we have to pass the bill so you can find out what is in it,” the speaker of the House was not making idle chatter. She was dead serious, and to this day we still haven’t grasped the enormity of what Congress has wrought in “reforming” health insurance and the health care industry.

As a nation of tinkerers and problem solvers, some can’t resist comprehensive reform because its allure is in the illusion that any problem can be cured if we are bold enough, or have enough courage (or throw enough money at it). What we fail to realize is that solving some problems creates others. The last immigration reform that was passed in 1986 amnestied 3 million illegal aliens and slapped penalties on businesses that knowingly hired illegals. What was never foreseen was that in the intervening 27 years, the number of illegals would triple, crossing the border without documentation would be virtually decriminalized in many places, and businesses would continue to hire illegals because enforcement was lax.

And now, once again, we are ready to pass a slew of provisions to “solve” the problem of immigration that address so many different questions that the overall effect of the legislation on the future of America has become a crap shoot. The idea of incrementally addressing what needs to be fixed by proposing legislation separately to deal with border security, guest workers, streamlining the visa process, and even a “path to citizenship” for those already here illegally will not be attempted largely because adherence to the concept of prudence — once the hallmark of the American constitutional system — has been abandoned in favor of showy, headline-grabbing, history-making law.

When will we ever learn?