“I think transparency is a good thing, and if Columbia is not using racial preferences, they should have nothing to hide,” said Richard Kahlenberg, director of the American Identity Project at the Progressive Policy Institute, a left-of-center think tank. Mr. Kahlenberg has pushed for class-conscious rather than race-conscious college admissions. But the data the government is demanding could be misused, he said, to suggest that “any attempt to create racial diversity even by race-neutral means is problematic.”