President Obama did not completely satisfy Hispanic members of Congress yesterday when he told them he had ordered a review of the administration’s enforcement of immigration laws. As the New York Times reports, what these lawmakers and the activists on behalf of the cause of illegal immigrants want is not a review but a presidential order halting deportations. In speaking of the review the president said he was concerned about the impact deportations have on the families. The question is how far the president, whose administration has actually reportedly deported two million people since he took office, will go on this issue in disregarding the law and Congress. Coming at a time when House Republicans are already up in arms about the president’s selective enforcement of other measures like his ObamaCare legislation, a decision to effectively annul immigration laws would be something akin to a declaration of war on Congress.

A deportation suspension would appeal to a Hispanic base that the president badly needs to turn out for Democrats this fall, as well as to his party’s base. But it would be a terrible mistake. Doing so would not only lend even more credence to the accusations being leveled at Obama about his contempt for the Constitution. It would also kill any hope for immigration reform for the foreseeable future.

The president’s concern for the families of the deported should not be dismissed by conservatives who are used to trashing everything the president does. Tearing apart these families, many of whom are legal residents or American citizens, takes a toll on our social welfare system. With an estimated 11 million illegals in the country, enforcement of these laws is, at best, haphazard and often arbitrary and capricious. Those caught by the Immigration and Naturalization Service are often in legal limbo for indefinite periods where due process is not always a given.

But while those affected deserve compassion, the fact remains that a system that not only tolerates the flouting of the law but also actively encourages it from the very top of the political food chain is one in which the rule of law has collapsed. It’s one thing for pro-immigration forces to call for a change in the laws to allow those who have entered the country without permission to have a path to legality or even citizenship. It’s quite another to say that the president should single-handedly abrogate the laws of the land.

Critics of Rep. Trey Gowdy’s proposed legislation that would allow Congress to sue the executive branch to enforce the law are right to point out that presidents have been selectively enforcing the law since the earliest days of the republic. Even if Gowdy’s bill passed, no court would touch a dispute that would be rightly understood as essentially a political controversy rather than a legal one. But if the president goes down the path of suspending all deportations, we will have passed a critical tipping point toward the creation of a new super-imperial presidency that transcends law or the Constitution.

That should worry everyone. But doing so should particularly concern immigration activists who still hope that Congress will act to fix a broken system. Though the bipartisan comprehensive immigration compromise that passed the Senate has no chance of getting through the House this year, supporters of the measure should not treat that as the end of the battle. There is a decent chance some kind of reform will pass in the next Congress no matter whether it is still split between the parties or under sole Republican control. But if Obama unilaterally annuls the existing laws by suspending deportations, it will worsen the split on the issue in the country and especially in Congress. If Congress no longer believes the executive branch will secure the border—an essential part of any possible immigration fix—there will be no way to convince them to change the system. Such a move could end any chance of reform for the foreseeable future.

With that in mind, Obama needs to tread carefully on deportations. As much as he likes to rule on his own, this is one executive order that he should never issue.