In general anytime you are pulling something wheeled behind you I would believe it is towing. And if you take into consideration the oppurtunity to extract money from an individual for the purpose of supporting the state, the answer becomes an emphatic YES.
And in thinking about this possibility, I wonder how long it will be before some state government decides they want BIG evil carbon spewing vehicles to pay, so lets start ticketing the ones towing a vehicle without a seperate specific trailer plate, instead of a vehicle registration plate.
Some petty beauracrat will probably try it one day.