An IMMIGRATION CAMPAIGN

Legislation is best reply for GOP

At a stroke, President Obama will protect, at least for the remainder of his term, more than 4 million illegal immigrants from the threat of deportation. He justifies the move as an act of "prosecutorial discretion." The president always has had authority to calibrate and prioritize the enforcement of immigration (and other) laws, but this wholesale reinterpretation amounts to ­overreaching.

Obama, a former constitutional law professor, has said as much, explicitly and many times. "Now, I know some people want me to bypass Congress and change the laws on my own," he said in 2011. "That's not how our democracy functions. That's not how our Constitution is written." He was speaking to La Raza, one of the groups pressing for unilateral action. Now those groups have won the day, though it may be a Pyrrhic victory.

On Thursday, they organized watch parties to see Obama's speech. On Friday, the president traveled to Nevada to celebrate in a purple state. The move has the feel of a political campaign, not a soberly considered act of governance.

Inevitably there is arbitrariness in the fine print. Why is it legal to protect the undocumented parents of citizens from deportation, as the executive order does, but not the parents of undocumented children, whom Obama has already shielded from immigration enforcement? Why is it all right to extend work permits to immigrants here illegally, but not health insurance under the Affordable Care Act? Immigration law, by its nature, involves setting arbitrary limits that leave millions unfairly on the wrong side; all the more reason to insist on the legitimacy of constitutional lawmaking. Obama was right to argue Thursday that otherwise law-abiding undocumented immigrants deserve a route out of the shadows. But unilateral action is not the right way to achieve that.

There is a smarter way, for the nation and the Republican Party. We realize it will not be the GOP's first impulse. But by fixing the nation's broken immigration system on their own terms, Republicans could negate the president's fiat, which, after all, is provisional and partial; assert their prerogative as elected lawmakers; repair their standing with Hispanic voters; and demonstrate an ability to be constructive.

If Republicans want revenge, in other words, they have a ready way to take it. It's called legislation.

FROM AN EDITORIAL IN THE WASHINGTON POST