Even fewer if you have a gerrymandered election system. Steve Bannon, now senior advisor to Trump, is on the board of Cambridge Analytica, a company that built (and presumably enabled the exploitation of) psychological profiles to maximize shares/distribution of content on social media, targeting specific geographic clusters:

1: http://www.spectator.co.uk/2016/12/the-british-data-cruncher...

2: https://en.wikipedia.org/wiki/Cambridge_Analytica

3: https://www.theguardian.com/technology/2016/dec/04/google-de...

The Trump campaign paid this group millions of dollars beginning in the summer of 2016.