There is only one way that this could be made fair.
First make the citizens in each state responsible for paying the sales taxes the state dictates.
(These are the people who do actually pay the tax.)
Second, release the local businesses from being tax collectors. This will make them equal to the on-line competition.
Third, wait for the backlash.
In my state of Illinois, I am tasked with paying sales tax on on-line purchases. However the state does not provide any guidelines as to what is taxable and at what rate. For example some "candy products" are taxable, and some are not based on the ingredients. So until the state provides me with the rules, I have no way of determining how much, if anything, I owe.