In the sobering and eye-opening HBO documentary “Kill Chain: The Cyber War on America’s Elections,” we see clips of various government officials and security specialists claiming America’s voting machines are too clunky and old-fashioned to be hacked.

The comments are remarkably similar:

“From what we determined, no voting machines are connected to the Internet …

“Voting machines are not connected to the Internet …”

‘Kill Chain: The Cyber War on America’s Elections’: 3 out of 4 CST_ CST_ CST_ CST_ CST_ CST_ CST_ CST_ HBO presents a documentary directed by Simon Ardizzone, Russell Michaels and Sarah Teale. Debuts at 8 p.m. Thursday on HBO and streaming on HBO Now, HBO Go and HBO on Demand.

“They are non-network pieces of hardware that are not connected to the Internet …”

“Those things are not connected to the Internet …”

Cut to one Harri Hursti, the rotund, avuncular, legendary Finnish expert on hacking and voting security, who has just purchased three commonly used American voting machines for $75 apiece from an Ohio recycling vendor he found on eBay, I kid you not.

Hursti plugs in the machine, turns it on — and the first thing that pops up on the screen is an option to connect to a local area network. So much for the protected-by-being-outdated argument. As Hursti and other cyber security specialists explain, even when we’re voting with paper ballots, there’s always a thumb drive, or a USB memory stick — some kind of removable media device, which means there’s always the opportunity for someone to mess with the process.

From directors Simon Ardizzone, Russell Michaels and Sarah Teale, the same team behind HBO’s 2006 Emmy-nominated doc “Hacking Democracy” (which also “starred” Hursti), “Kill Chain” is at times a bit dry and tough to track, what will all the techno-terms and cyber-chat, so to speak. But in its most effective moments, it’s like something out of a dramatic/comedic feature film on the order of “The Big Short.” Our jaws drop as we learn stunning truths about America’s messy, outmoded and far too vulnerable voting system.

As author and journalist Sue Halpern explains, “Our elections are run locally. There’s no national election system. It’s up to the counties and the election officials in those counties — they get to decide how we vote, what machines we use. ... Paper ballots, [votes from] electronic machines, touchscreen computers … all of the votes go to a central location.”

Three main vendors run the vast majority of election machinery in this country: Dominion Voting, Elections System & Software, and Hart. They don’t reveal anything about how their systems work, because it’s all proprietary. (All three companies declined to be interviewed for the doc.) It would be an understatement to say “Kill Chain” makes the case these machines are hardly tamper-proof.

Time and again, the experts say when government officials proclaim “there’s no evidence votes were changed” in a particular election, they’re missing the point. The goal of the bad actor is to cause chaos — often between cycles, not during the actual election.

“Malware can infect machines between election cycles,” says one expert. “It would be very easy to write a piece of software into [an American voting machine] that would silently change votes as they come in and there would be no evidence [of it happening]. This is a relatively simple machine. It wouldn’t be hard to remove traces it had been tampered with.”

Case in point: In an election in a heavily Democratic precinct in Georgia, there were seven machines. Six machines showed easy wins for Democrats in every statewide race. One showed Republicans winning every race by a large majority. A study found that mathematically, there was less than a one in a million chance of that happening.

Sometimes the numbers add up in a way that doesn’t add up.