unfortunately that would mean two firstly things only swing states would get to hear what politicians are actually saying and secondly to reach everyone the primary process would have to start even earlier so the candidates would have a chance to give enough speeches before early voting

I'd give it about 20 years before humanoid robots can be indistinguishable from originals without an x-ray or similar — covering them in vat-grown cultures of real human skin etc. is already possible but the robots themselves aren't good enough to fool anyone.