Trump catapulted a baseless smear about Omar's marriage from the online fringes into the political mainstream
President Donald Trump shows passion while delivering a campaign rally speech at the Mohegan Sun Arena. (Evan El-Amin /

President Donald Trump pushed a baseless smear against Rep. Ilhan Omar (D-MN) that originated in the online fringes -- as he incited a North Carolina rally crowd to launch a racist chant.

The president told his supporters in Greenville that he'd heard Omar had married her brother, an evidence-free claim that was first posted online in August 2016 as her political career began to take off but has since gained traction in conservative media, reported The Daily Beast.

A self-identified Trump supporter going by the name "AbdiJohnson" first made the claim in a thread called "ILHAN OMAR MARRIAGE FRAUD EXPOSURE" posted on the Somali Spot online forum as the Minnesota Democrat appeared to be on the brink of taking down a longtime incumbent the Democratic-Farmer-Labor Party primary for a state legislature seat.

The thread has since been deleted from the forum, but remains online elsewhere.

AbdiJohnson claimed that Ahmed Nur Said Elmi, from whom Omar was then separated, was actually her brother, and suggested the pair had married to help him enter the U.S.

The user, who was a notorious troll on the site, never showed any evidence of his claim -- but that didn't stop Minnesota lawyer Scott Johnson from posting about the unsubstantiated rumor on his Power Line blog, which gained fame during the 2004 election by discrediting forged documents on George W. Bush’s National Guard service.

“Let me note here that Omar’s marriage to her brother, if it occurred in fact, is illegal under Minnesota law,” Johnson wrote.

Johnson has continued to write stories claiming the pair are brother and sister as recently as Thursday, and he admits that his claims are based mostly on the Somali Spot post, as well as unspecified "social media evidence" and his own suspicions that she's "hiding something."

The story was then pushed by the conservative Minnesota politics site Alpha News, which examined social media accounts that may or may not have belonged to Elmi, who referred to Omar as his sister.

However, Somali language experts pointed out that "brother" and "sister" are polite terms of endearment in Somali and don't necessarily indicate a familial relationship.

Omar has shown reporters photos of her immigration documents listing her siblings' names, and Elmi was not among them, but that hasn't stopped conservatives from pushing the claims.

Her complicated marriage history -- which includes religious and legal marriages, off and on, to Elmi and another man, Ahmed Hirsi -- have buoyed the conspiracy theory, and Omar was fined $500 in June for improperly using campaign funds to resolve joint tax issues with Hirsi, which conservatives have pointed to as evidence of suspicious activity.

The claim gained additional traction after her election in November to the U.S. House, as PJMedia blogger David Steinberg started writing a series of posts claiming Omar and Elmi have the same father that rely entirely on unnamed sources.

Anti-Muslim activist Laura Loomer, bumbling conservative operative Jacob Wohl and Twitter user Ali Alexander went to Minnesota earlier this year to investigate the claims, but all they turned up were social media posts that had already been reported.

Notorious conspiracy monger Jim Hoft, of the Gateway Pundit blog, has attempted to prove Omar entered the U.S. illegally, while The Daily Caller and other right-wing websites have tried to disprove Omar's claims in a divorce filing that she did not know how to contact Elmi.

It's not clear how that would resolve whether or not the two were siblings.

It's also not clear how Trump first learned of the rumors about Omar's marriage, but the smear has been pushed all summer by high-profile conservatives such as Dinesh D'Souza and Rush Limbaugh, and Hoft visited the White House last week for a social media summit with the president.

Limbaugh pushed the rumor Monday on his radio program, and conspiracy monger Jack Posobiec posted an Alpha News video hours before Trump launched the claims into the mainstream at his Greenville rally.