President Obama’s announcement Friday that he will temporarily halt the deportation of some young students and veterans who are in this country illegally is a step that is in some respects worrisome — and yet one he’s right to take.

Students who were brought to this country illegally as children by their parents and have grown up here should not be the top enforcement priority over criminals who pose a threat to communities; veterans who have served in this nation’s military similarly are owed preferential treatment under its immigration laws. Allowing these people to remain here is the humane thing to do.

But using administrative authority to achieve that goal presses the limits of presidential power. In this case, there are reasons to be wary of its reach — deciding, even temporarily, not to prosecute an entire group of lawbreakers comes perilously close to making new law — but also to recognize that the complexities and history of immigration suggest Obama’s move is defensible under the circumstances.

Federal authorities lack the resources to expel all of the estimated 11 million illegal immigrants living in this country. Given that fact, it makes sense to set priorities and use prosecutorial discretion to decide who should be targeted for deportation. Previous presidents have exercised such discretion to temporarily stave off deportation of immigrants or to set enforcement priorities. In 2007, President George W. Bush halted the deportations of Liberians, whose country was emerging from a civil war.

Obama’s action differs in scale — rarely have whole classes of immigrants been granted protection without a crisis back home — but it builds on ample precedent. Moreover, it is limited in scope: Only immigrants who came to the country before they turned 16, have lived here for at least five years, who lack any serious criminal convictions and are students or high school graduates would be eligible, as would honorably discharged veterans.

Friday’s announcement angered anti-immigrant groups, which complained that the president’s action amounts to little more than a blanket amnesty. That’s not true. His order defers action against those it covers for two years and allows them to work during that period, but it does not assure them a permanent place in this country.

Because of that, the president’s move only interrupts the deportation of young men and women who should be allowed to stay; it does not secure their futures here. What is needed is a lasting solution, but Obama cannot deliver that on his own. It required the full exercise of his presidential power to grant temporary reprieve to these worthy recipients. It will require the partnership of Congress to produce the change in the law that will make those protections permanent.