>> NARRATOR: Donald Trump wasn't

the only one who seized the

opportunity to exploit the

nation's division.

Vladimir Putin did it, too,

using a cyber-attack to strike

at the fault lines of American

democracy.

>> The effectiveness of this

interference from Russia depends

on a couple of things.

(people speaking Russian)

>> It depends on the

polarization of politics in

America.

There were divides, and Russia

was pushing out material that

exploited those divides, that

broadened them, that called

attention to those divides.

(phone chimes)

>> NARRATOR: Posts on black

power...

>> "Staying woke, uplifting our

people."

>> "We are proud to be black and

stand..."

>> NARRATOR: On Southern

pride...

>> "The Confederate flag

represents heritage..."

>> "Join our fight to save

Southern heritage!"

>> NARRATOR: Russian attacks

played into deep-seated fears.

>> "If I win, Clinton wins!"

>> NARRATOR: Exploiting both

sides on the most divisive

issues.

>> "Stop police brutality!"

>> "Blue lives matter!"

>> NARRATOR: Immigration.

>> "It's time to get rid of

parasites!"

>> NARRATOR: Guns.

>> "I'll keep my guns..."

>> NARRATOR: Race.

>> "White kids chant N-word in

school bus."

>> And that's when I realized,

"Uh-oh, things have gone too

far."

There was a tipping point that

took place.

And I think the Russians didn't

create that tipping point, but

they exploited it.

They saw the fissures of... of

division.

They saw these, these... these

pivot points and they went right

for them.

>> NARRATOR: Trump, himself

sowing discord and chaos,

encouraged the Russians to

continue their attack and target

Hillary Clinton and the

Democrats.

>> I will tell you this: Russia,

if you're listening, I hope

you're able to find the 30,000

emails that are missing.

>> I think they started their

operation to intervene in the

election with the idea of

simply sowing discord, and, uh,

weakening the United States as a

country by doing so.

It only later became, uh, a

mission to actually specifically

elect Donald Trump.

(man speaking Russian)

>> NARRATOR: To help Trump, the

Russians created fake news about

Hillary Clinton.

(reporters speaking Russian)

>> Vladimir Putin certainly has

our number as a country.

He understood how easily

Americans could be turned

against each other with

Facebook.

What Facebook does is obliterate

the ability to tell the lie from

truth.

Where what is real, what is

fake, is not discernible and not

knowable.

And the consequences of that,

for a democratic republic, are

frightening, at best, to think

about.

>> NARRATOR: One particular

conspiracy theory was aired in

America by a Russian propaganda

network, RT.

>> ...theories about her

health caught on...

>> NARRATOR: Exaggerated and

questionable stories about

Clinton's health...

>> Under a microscope are

Clinton's falls, coughs, and

head motions.

(reporters talking)

(laughing)

>> Have you talked about vice

presidential possibilities with

Senator Warren?

>> You guys have got to try the

cold chai.

>> This video filmed in June

went viral and started a slew of

rumors that Clinton may have had

a seizure.

>> We were watching stories

about Hillary Clinton appearing

on Russian propaganda websites

like Russia Today and Sputnik.

>> A Democratic frontrunner has

been forced to refute rumors of

her deteriorating health, maybe.

>> And then somehow ending up in

very similar form in the right-

wing media ecosystem of the

United States-- Breitbart,

InfoWars, even Fox News.

>> What was once a concern

voiced in whispers is now

getting mainstream attention.

We're talking about Hillary

Clinton's health.

>> Some have said it's like a

mini-seizure.

What does it look like to you?

>> It could be a post-concussion

syndrome.

You know, your balance is off,

you're-- you're dizzy all the

time, your memory is off...

>> NARRATOR: It was invented,

overblown, but it didn't matter.

>> The fact is, she's out there

giving speeches every day and

has to cancel them having these

coughing fits.

>> New questions tonight about

Hillary Clinton's health.

>> Good evening, it was a

dramatic moment that's already

being watch and re-watched.

>> The episode this morning is

raising more questions about her

health...

(reporters speaking Russian)

>> NARRATOR: And the candidate

made the most of it.

>> And she can't make it 15 feet

to her car, give me a break.

Give me a break.

(cheers and applause)

Give me a break!

>> NARRATOR: As the fake news

spread, conservative talk radio

host Charlie Sykes saw how it

hardened the divide.

>> I'll tell you what my

experience was in 2016.

That the flood of these

misleading or outright false

stories was increasing.

In the past, I'd always been

able to push back on my audience

and say, "Okay, you understand

this is not true.

This is not the case."

You know, "There are not bodies

stacked up in the Clinton

Library, and here's the source

of all of that."

By late 2016, though, I was no

longer able to do that.

People were not willing to

accept the corrections.

And Donald Trump is counting on

this, and this does

fundamentally change our

politics.