host -t ns twitter.com: ns3.p34.dynect.net, ns4.p34.dynect.net, ns1.p34.dynect.net, ns2.p34.dynect.net.
host -t ns amazon.com: ns3.p31.dynect.net, ns4.p31.dynect.net, ns2.p31.dynect.net, pdns6.ultradns.co.uk, pdns1.ultradns.net, ns1.p31.dynect.net.
"How do all these major players have singly-homed DNS"?
Though if they targeted electric grid, water, and public transport, starting early in the day and choosing the regions by their populations political leaning, it could easily have an effect on the result itself.
Control the message, and through that the actual votes cast.
Of course, I have no information on the security model of the pre-election preparations and post-election tabulation, but luckily results for each polling place are also posted for the public to inspect - media outlets and campaigns can verify the tabulation themselves with a slight delay.
https://www.techdirt.com/articles/20160912/16553435504/fbi-d...
Of course, he said nothing about internal rigging: