Ohio's license plate policy appears discriminatory when we consider how much money the state could save with a single license plate. Further when several states require only a single license plate why should Ohio require two. However some states such as Michigan currently requiring only one license plate are reconsidering having two license plates instead of one in order to help law enforcement. Front plates are actually helpful even for drivers because the reflective surface helps divers by warning them when an oncoming vehicle's headlights are switched off.
It is not discrimination to point out when someone has committed a crime by indicating it on their license plates, as long as they make everyone do it. It would be discriminatory if public officials, cops or anyone else was excluded from the DUI plates, but as long as it applies to everyone it is fair.
There is nothing inherently discriminatory about the law itself. However, in some cases it can be used as an excuse for discrimination. I am not an Ohio resident, but not having two license plates on your car seems like a minor offense. I would imagine that the law is not always enforced. However, if a police officer finds a person "suspicious" (which in some cases may mean that they have a certain skin color), they can use that law as an excuse to harass the person. Getting rid of the law certainly will not end profiling or discrimination though.
This policy is not really discriminatory but is more like greediness on the part of police officials. People lose license plates all the time through some unknown circumstances. As long as there is one license plate on the vehicle then there shouldn't be a problem. This outlet just gives police an easier way to give out tickets and get more money from the tax payers that already pay their salary. It truly is never enough.