The Trump campaign and Republican National Committee for months have promised to recruit as many as 50,000 poll watchers to monitor voting locations on Election Day. The campaign’s “Army for Trump” website has contributed to that effort, urging supporters to join the “army of supporters fighting to re-elect him in 2020.”

But more-extremist supporters appeared to be joining that effort Wednesday, raising the prospect for confrontation and intimidation at polling locations.

“I got shivers,” Andrew Anglin, the founder of the neo-Nazi website the Daily Stormer, wrote in a post Wednesday. “I still have shivers. He is telling the people to stand by. As in: Get ready for war.”

Members of the Proud Boys repeated Trump’s false claims about election fraud in Philadelphia. The Official Michigan Proud Boys account posted a new logo on the encrypted messaging service Telegram based on Trump’s phrase: “Stand Back and Stand By” and reposted his tweet: “Must have a fair Election.”