Sortition versus manipulation?

I have been studying the claims that the Trump election was the product of clandestine manipulation of voters by sending them false information so targeted to their personal characteristics as to have a decisive influence on their voting behaviour.

The data firm Cambridge Analytica claims to have profiles of nearly everybody in the USA, based on information about them collected from the internet. These profiles enable predictions of a very high accuracy of what sort of information will be accepted by particular people and what influence it will have on their voting. It is not very likely that such manipulation would induce many Democrats to change their vote, bit it might leave them less likely to turn out for Hillary. It could easily account for bringing fringe Republicans to vote. The Trump campaign spent relatively little on conventional media. They got so much free! But they are said to have spent heavily on covert manipulation.

A first reaction is that we have another argument against voting and all that goes with it in current practice. But further reflection reveals a danger even to sortition. The members of a body chosen by sortition can be identified and their prejudices cultivated to pervert their view of the facts they are considering. It need not be very expensive, since they are relatively few in numbers, and well worth the cost to a body with big interests at stake. It would be more attractive than lobbying in many circumstances.

The only remedy I can see is insistence that all the proceedings of public decision-making must not only be available to all, but open to comment at every stage so that untruths are challenged and patterns of deceit uncovered.