The problem is how to fairly accomplish something like this without it being onerous. 

What tax rate do you use, how do you collect and distribute the taxes?

It sounds like there are ways to do it...until you have a company in NJ selling to someone in CO and NJ and CO both want a share of the tax.  Then you find that the tax in Colorado is a bear to calculate anyway. What tax rate do you use for Denver to NJ vs Aurora to NJ and who gets what. Then you have all the tax licensing.  Does a company in NJ have to do the paper work and pay a fee to collect tax for Denver?  Then you have the auditing.  Denver audits sales taxes all the time.  Now they are going to have a lot more work to do.  I only really know Colorado, we've made a mess of sales tax calculation and collection.  I would assume we aren't alone in that. 

We could do it with a national sales tax at a set rate that divides between fed and the 2 states involved.