A mob of Black Lives Matter demonstrators berated and threatened a Fox News reporter in St. Paul, Minn., when the reporter asked the protestors why they were blocking a highway on July 9.

“Get the f… out of here,” the lead organizer frantically chanted into the face of the stunned reporter, who politely defended himself by saying, “I asked you… [to] tell me why you are here.”

The demonstrators pushed up against the reporter, forcing him backwards towards the protection of police, while another person seems to say “we’re going to knock his ass out.”

The video illustrates the risks and benefits of President Barack Obama’s determined, high-risk gamble as he tries to spur African-American emotion and anger before the critical 2016 election.

He has repeatedly urged African-Americans to make the issue of police tactics and practices into a political issue, after bitterly complaining that low-turnout cost him the Democrats’ Senate majority in 2014. “All Americans should be deeply troubled by the fatal shootings of Alton Sterling in Baton Rouge, Louisiana and Philando Castile in Falcon Heights, Minnesota,” Obama said in an July 7 message posted early afternoon on the White House’s site and on Facebook.

He’s been so successful in promoting the issue that some African-Americans are becoming aggressive and violent, mostly notably by killing five cops in Dallas on July 7.

That violence is a political problem if it causes a massive non-violent pushback at the ballot-box by voters against the candidate he is trying to help in 2016, Hillary Clinton.

So Obama is now trying to calm African-American anger to prevent any peaceful pushback by ordinary Americans. “Everybody involved in the Black Lives Matter movement… I want all of them to maintain a respectful, thoughtful tone – because, as a practical matter, that’s what’s going to get change done,” Obama said July 10.

That’s not easy, in part, because some of the activists he helped create are very emotional.

The St. Paul organizer chants ‘Get the f… out of here” roughly eight times in the video. The crowd joins in, saying “get out of here” eight times.

“He’s the face of white supremacy… you are a racist, supremacist… you are a disgrace to journalism,” the organizer shouts through her megaphone.

The organizer began her shouting by demanding the reporter help the protestors. “Are you fighting for what re’w fighting for?” she shouted.