A white, self-described "redneck" who supports Donald Trump says there's a war coming in November no matter who wins, but if Joe Biden does he's threatening to start it ... and that's raised alarm bells with authorities.
In the video spreading like wildfire on social media, a bearded man ID'd as Zachary Poole makes it clear he believes Trump 2020 will prevail on Election Day ... but predicts members of Black Lives Matter or Antifa will try to start a war when that happens.
Poole insists he and his people are ready for this, but if things don't go their way and Trump loses, he warns -- "We comin' ... and we comin' strong."
Law enforcement sources tell TMZ ... the video was almost immediately reported to the Williamsburg Village PD in Ohio, along with concerned citizens forwarding it to the FBI.
It's being taken very seriously too -- we're told Poole's online post and social media are being monitored by police, though no official investigation has been launched or charges filed.
Our sources say the Williamsburg police have also contacted the FBI about the video because they feel Poole's words could be perceived as a threat against people of different races and religions ... and the feds have more experience with hate crimes.
The timing of the video is interesting too ... as it comes on the heels of President Trump's ominous message to the far-right group, Proud Boys, during the first debate.
There's speculation Poole might be affiliated with the group, but we're told law enforcement could not confirm that ... and are still in the early stages of gathering info.