It was already true even before the financial crisis of 2008 that the pace of demographic change in the United States was outpacing many conservative voters’ tolerance. Since then, two things have happened. First, Americans have come to feel much less economically secure. Second, the baby boomers have begun to retire, intensifying already intense anxieties about the sustainability of Social Security and Medicare. To add on top of that a costly new program that appears to compete with those older programs for the benefit of a different population…that’s asking for trouble.

The deed is now done, and—as House Republicans just painfully rediscovered—done beyond undoing. The political task ahead is to minimize the deed’s negative consequences: economic, fiscal, political, and social. Instead, the Obama administration seems intent on maximizing such negative consequences. “You know that demographic change that’s making you so hostile to new social welfare programs? Let’s have a lot more of it! And faster!”

That’s folly—the kind of folly that rends nations and weakens governments. Back in 2008, Barack Obama promised “change.” He delivered. If he wants to protect and preserve his accomplishment, he’ll understand that even change has its limits, and that change becomes most secure when administered in tolerable doses. Immigration reform atop health-care reform is one change too many. Leave the next chapter to the next president.