Tesla's Sales Moat (Seeking Alpha)
In short, franchise laws protect manufacturers from opening stores that would compete and take business from the existing dealerships. As covered above, dealerships are collectively very large, and since they happen, collect the sales tax from the consumer, they become one of the largest tax payers in a given state. This has given them tremendous influence over Congress, and with the power of dozens of dealer associations across the country any manufacturer attempts to start a sales operation has been shut down.