Is MN's gas price law working?

Minnesota's gas price law says that whatever price the retailer paid for it the retailer must sell it for a minimum of 8 cents over the wholesale cost. This was designed so that the larger gas retailers would not hurt the smaller gas stations. However most of the stations that have been fined under this law have gone to the smaller gas stations. I believe that this law is actually hurting the gas station owners it intended to help. Some legislators tried to sponsor bills that would repeal the gas price law this last session. In fact there is a federal law that already deals with this kind of situation. Its the Sherman Anti-Trust Act. One of the provisions in this act says that a business must not lower their price below wholesale for the purpose of eliminating their competition. For example if a chain store like Super America would sell temporarily under the wholesale cost and either transfer funds from other stores or wait until the local store goes out business. The local store would go out business because they cant lower their price or transfer funds from another store. Then the chain store will increase the price well above the wholesale price since it is no longer in competition with the local store.