It also has the effect of pushing as many people into the +buckets as possible, making it so all marginal cases are included. This could be a modern incarnatio

It also has the effect of pushing as many people into the +buckets as possible, making it so all marginal cases are included. This could be a modern incarnation of the 'one drop' rule, thinking that if you're part minority, that is still the most important part of your makeup. Or, more likely, it's to inflate numbers as much as possible for PR.