No one would recognise the light if it was shone right in their eyes. One could not tell who was telling the truth and who was pulling the wool over our eyes in the last referendum re. staying the EEC, I have no expectation that this referendum will be any different.
Any public figure expressing an opinion will have their own reasons for wanting to pick one side or the other, and they're going to try their best to persuade regardless. But if the majority of folk fall in with the wrong lot they'll only find out when it is too late, and then they will depend on the next generation, or the one after that, to change things. But more resent generations won't have the experience to be any better able to judge truth from lies than the previous generation was. So it is still that the most skilled orators/debaters have the best chance of 'winning the day' regardless of the truth of the matter.