New Delhi, May 2 -- For decades now, the push for an increase in reservation, over and above a cap set by the Supreme Court in 1992, has come up against an immovable object in the form of constitutional courts.

But given that the courts have insisted on quantifiable data to justify state action, the caste census announced by the Union government on Wednesday could change things.

In 1992, a landmark decision in the so-called Indira Sahwney case by a nine-judge bench of the Supreme Court laid down the rule that as a norm, reservation cannot exceed the 50% threshold. In the years since, laws by states and Centre providing reservation beyond this limit came to be challenged in the top court, and judicial decisions maintained the sanctity of...