President Barack Obama won in the Electoral College by healthy margins in 2008 and 2012. The 1972, 1980, 1984, 1988, 1992, and 1996 presidential elections were also relative blowouts in the Electoral College.
A second condition needed for a hacked election is an available attack vector. Unfortunately, most election security experts don’t have a hard time imagining one.
Fifteen states still use outdated electronic voting machines without attached printers, which can be used to audit their internal vote counts. More than half of the states are still using these direct-recording electronic machines or DREs, with or without attached printers, and many voting security experts say both types of DREs have vulnerabilities.
Among the states using DREs without paper trails are potential swing states Pennsylvania, Virginia, and Florida. Those states don't use DREs statewide, so hackers would have to research the jurisdictions where DREs are still being used.
Potential swing states using DREs with attached printers in some or all jurisdictions: Ohio, Nevada, Wisconsin, and North Carolina.
The U.S. has more than 5,000 voting jurisdictions, noted Douglas Jones, a computer science professor at the University of Iowa. "Some run very tight ships, but some are sloppy," he said by email. "Because they're all at least a bit different, you'll need to pick a jurisdiction that is vulnerable and where the number of votes you can steal is enough to make a difference."
Finally, hackers would need the resources to pull off a major election system breach. They would probably need a small to medium-size team, significant funding, and the organizational discipline to keep the hack secret. A leak of a hacked election could lead to criminal charges and would almost certainly turn public opinion against the winning presidential candidate. News of a hacked election could damage the winning candidate’s political party for decades.
"A medium-sized conspiracy might be able to hack one or two swing states," said Jones, who has researched voting-machine security. "To swing a close state, it might be sufficient to swing just one medium or large-sized county."
With the number of voting jurisdictions in the U.S., "it is quite likely that you'll need a small team to hack each jurisdiction you select even if they run the same voting machines, because of the differences in election administration," he added. "So the size of your conspiracy -- and your risk of exposure -- grows with the number of counties you attack."
Still, there’s been evidence this year of outside hackers, like Russian teams, trying to raise doubts about the U.S. election. "If you're a state-level player with national-scale resources, you can set up multiple teams," Jones said.
If those conditions are all in place, here are three hacking scenarios:
Sign up for CIO Asia eNewsletters.