Media playback is unsupported on your device Media caption The billionaire financier and philanthropist has become a divisive figure in global politics

Disinformation about George Soros and untrue stories detailing his alleged connection to the migrant caravan in Mexico are making headway among American voters on social media.

Right-wing media organisations have portrayed the Hungarian-American billionaire as a leftist bogeyman using his money to derail the US political system, usually through unproven rumours that his largesse not only funds NGOs and campaign groups but also the migrants in Mexico.

It's a narrative pushed by President Trump himself, who claimed on Twitter that women protesting the Justice Kavanaugh confirmation hearing were "paid for by Soros and others". He's also made the migrant caravan and immigration issues central part of his mid-term election push.

Both "real" social media users and what appear to be bot accounts have been spreading disinformation aimed at Mr Soros and his Jewish background, even after the Pittsburgh synagogue shooting which left 11 worshippers dead.

Soros the bogeyman

Many Twitter users have been enthusiastic in following the right-wing narrative that George Soros is deeply involved in funding liberal causes, from paying people to protest against Brett Kavanaugh, to handing out cash to encourage migrants in the south of Mexico to move toward the American border.

Rumours that Mr Soros has been funding migrant caravans go back months, with one item on right-wing website One News Now dated 1 May bluntly proclaiming that "Leftist billionaire George Soros is funding the well-organised anti-Trump migrant caravan invasion from Central America" which is "attacking the US border" as part of a "refugee invasion".

It takes as its source, other right-wing websites, WorldNetDaily and CNS News.

Among the slurs against the financier is the continued spreading of the discredited story that he was a member of the Nazi SS.

Image copyright TWITTER Image caption This is not George Soros: A meme repeats the lie that he was a member of the SS

One Twitter user tweeted a meme last week which repeated the accusation, receiving more that 6,000 retweets before it was deleted following a strong rebuke from the Auschwitz Memorial account.

"This is a lie. The man in the picture is Oskar Gröning, a member of the SS garrison of the Auschwitz concentration and extermination camp," the site commemorating victims of the Nazi genocide said.

But the strength of polarised opinion around the meme, still available on Twitter shows that the "alternative facts" broadcast both in right-wing media and on social platforms are being believed and shared by many users ahead of the mid-terms.

Image copyright GUILLERMO ARIAS/AFP Image caption Some sections of the US media and some social media users claim that the migrant caravan is trying to 'invade' the United States

Viewed over 2.4m times on Facebook, for example, is a video posted in April by former Fox News presenter Glenn Beck titled "George Soros is funding the migrant 'caravans' to the US". The video has been re-purposed by right-wing Twitter users to justify their support for President Trump sending troops to defend the southern US border.

American press reports say that the slow-moving caravan, numbering around 7,000 people, is still more than 1,000 miles away from the US border, but Twitter users, such as @MrFreddyColon who has over 64,000 followers, claim that the number could be as high as 50,000 before the caravan reaches the US.

This echoes stories seen on right-wing US TV networks, which describe the immigrant group as "diseased", "violent", or a likely cover for terrorists and criminals.

With the same narrative being pushed by the US president , it's hardly surprising that there is no shortage of people posting anti-immigrant opinions on social media.

Facebook fakery

Disinformation on George Soros is also present on Facebook, with groups such as "George Soros Exposed" and "Arrest George Soros" becoming more active in the weeks before the elections.

The latter group entertained a rumour in September - spread by QAnon activists - that Mr Soros may already have been arrested.

George Soros Exposed posted a meme calling him "the most evil man on this planet" along with a list of his alleged "crimes".

These groups tend to share memes already posted on other conservative pages spreading an extreme right-wing agenda, along with the predictable claims that the Pittsburgh synagogue shooting were a "false flag" operation set up to discredit the right.

Image copyright FACEBOOK Image caption Evidence-free claims are a staple of anti-Soros Facebook groups

Memes and hashtags battle it out

While genuine social media users from all parts of the US political spectrum post their opinions, there are also networks of accounts hoping to skew the conversation in their preferred direction.

Among the accounts identified by the BBC, @AnnaApp91838450 displayed typical partially-moderated bot behaviour "conversing" with other very similar accounts to look more "human" to the casual observer.

With nearly 80,000 followers, and TwitterAudit suggesting most are genuine users, the account seems to have gained a large follower base through its unrealistically high number of follows - over 50,000, and at least partial human curation with memes specific to the account.

It also shares large numbers of pro-Trump, pro-GOP and pro-right wing posts with other, similar accounts which feature typically patriotic names (George Washington's Axe - now suspended, Vet With A Cause, Deplorable Doug) and large follow-to-follower ratios.

Image copyright TWITTER Image caption Twitter users spread rumours that the migrant caravan is a cover for Islamic terrorists trying to reach America

But what sets them apart from regular Twitter users is the sheer volume of posts. These accounts post hundreds of times daily, both their own content mixed with retweets from conservative accounts, including Donald Trump, his family, and conservative news outlets such as Breitbart and Gateway Pundit.

Posts appear on these accounts every few minutes, heavy with hashtags and emojis, and almost always with an accompanying meme, animated gif or photograph. It could be easy to surmise that it is a full-time job for the person or algorithm operating any given account.

The huge number of hashtags, sometimes several in each post (#MAGA, #VoteRedToSaveAmerica, #StopTheCaravan are all seen frequently), suggests an attempt to hijack search results - and hence the conversation through volume of traffic.

Curated content seems to be in broken English, suggesting it is not the user's first language, and basic errors ("George Soro's" with an apostrophe) suggests the output is based more on quantity rather than quality.

They've also remained active virtually continuously since they emerged in the months before the 2016 election when the emphasis was on #LockHerUp, #DrainTheSwamp and #EvilHilary.

But with immigration and nationalism being prominent in the Republican campaign, the wave of extremist tweets continues, along with their claims that Mr Soros is the shadowy hand planning the demise of the United States.

BBC Monitoring reports and analyses news from TV, radio, web and print media around the world. You can follow BBC Monitoring on Twitter and Facebook.