Who knew that an article that appeared on Page 3 of the metro section of the New York Times nearly a quarter-century ago could have such resonance in today’s policy debates?

As part of its justification for President Obama’s executive action on immigration, the White House and its allies have repeatedly stressed that Obama’s action, in impact, is roughly equivalent to a step that George H.W. Bush took in 1990. The United States had about 3.5 million illegal immigrants in 1990, so 1.5 million would be about 40 percent of that number. Given that about 40 percent of the current number of undocumented immigrants would be covered by Obama’s actions, that 1.5 million figure is crucially important to the White House’s defense of the president’s decision.

Much of the news media, including The Washington Post, has repeated the 1.5 million figure as a fact in recent weeks. But it turns out that the number hangs on a slim reed.