President Obama has failed to do the one thing in his power that could help lift Haiti out of the morass that has engulfed it since the January 2010 earthquake: Order the Department of Homeland Security to admit into the United States the thousands of Haitian nationals whom DHS already has approved for U.S. visas.

He could expedite this orderly migration process immediately. It doesn’t take an act of Congress, literally. More than two years after an earthquake rocked an already struggling Haiti to its core, it’s baffling that he still has not directed DHS to act. After all, the initiative has bipartisan support in Congress. In fact, Rep. Ileana Ros-Lehtinen has taken a lead here, making the case — along with Sens. Bill Nelson and Marco Rubio — that kick-starting a so-called family-reunification program not only is the compassionate thing to do, it also makes great economic sense.

Many Haitian-American families, already legal and established here in the United States, have petitioned the U.S. government to approve visas for qualified relatives in Haiti. This is a normal process for many immigrant groups looking to get their relatives out of discouraging or dangerous homelands. Haiti clearly qualifies.

The earthquake made the situation even more dire. About 112,000 petitions have been approved, but the visas have yet to be issued to the people, who would be legal upon their arrival here. However, because Congress sets limits on how many people can be admitted from a particular country each year, approved Haitians face an up-to-11-year wait to enter the United States.

Given the devastation that Haitians on the island still confront day in and day out, bringing the approved Haitians here sooner rather than later would relieve some of the pressure on scarce resources in the stressed nation; and it would help prevent tragedies such as the recent drowning of desperate people taking to the sea in rickety, overcrowded boats.

Most important, once approved Haitians arrive in the United States and receive work permits, they can send money back home to help relatives who have so little. This, in turn, would send a needed infusion of cash into a gasping economy. In 2009, Haitians in the United States sent more than $1.5 billion in remittances to relatives on the island.

Ironically, President Obama has been on a winning streak when it comes to immigration issues. He recently signed an executive order granting work permits to undocumented young adults who were brought to the United States before they turned 16.

And on Monday, the U.S. Supreme Court struck down several provisions of Arizona’s overreaching immigration law, saying that the state inserted itself in an area that is the federal government’s purview — siding with the Obama administration’s view, though leaving the onerous “show me your papers” provision in place, unfortunately.

In addition, there is precedent for a Haitian family-reunification initiative. In 2007, Congress opened the door for the Cuban spouses and minor children of Cuban immigrants in the United States. Three years later, as president, Mr. Obama granted the program an extension.

This president clearly understands the impact that separating families — or reuniting them — can have on their ability to get on their feet and help relatives in their native countries.

So why the double standard, Mr. Obama? Give the order, and help make Haitian families whole here and on the troubled island.