Last Thursday, the New York Times reported that President Barack Obama might announce his long-awaited executive action on immigration this week. The order, which White House officials insist isn’t finalized, would give up to five million undocumented immigrants a temporary reprieve from deportation—and, in some cases, permission to work legally—according to the Times report.

Immigration activists think it’s clearly the right thing to do, Republicans think it’s wrong, and I’m honestly not sure who’s right.

The precise details of what Obama has in mind aren’t clear and those details matter. But the order would presumably allow the undocumented population to come in from the shadows—to work and to live with family members here legally, without fear of suddenly being apprehended and sent back home. As I explained in August, such a move would almost certainly be legal.

Existing immigration laws give the president clear and broad discretion to decide when and how borders and customs officials focus their enforcement efforts. Since authorities can’t deport all or even most undocumented workers anyway, the president can tell them which ones to make a priority—and which ones to ignore. By definition, any presidential order would be temporary; a successor could undo it easily. And it would not actually change the legal status of such workers. It would merely protect them from enforcement of U.S. immigration laws. That’s still very important and would make a significant impact on the lives of millions of people.

But five million is a really big number. And whether giving a reprieve to such a large population crosses a line of democratic norms is still a murky question—murkier than many liberals seem to recognize. This would be a major change to U.S. immigration policies, without any input from Congress and in the immediate aftermath of an election in which the president’s party was resoundingly defeated. That’s not to say the GOP earned a mandate from the election. They didn’t. But Republicans won, and they were on the side of more restrictive policies. Given all of this, it’s tough to argue that the public wants Obama to announce a big unilateral move on immigration.