It would be easy for a program to generate a random list of voters with the correct demographic ratios.
A 2nd program then datamines their social media, email and browsing history to calculate who they are likely to vote for.
Far more accurate than traditional polls where they have to deal with diminishing land lines, shy voters and those who deliberately lie to the pollster.
Most modern polls are push polls designed to sway or measure public opinion.
Should have been: measurethe effect of propaganda on public opinion.