Emails obtained by ABC News show the Trump campaign calling on supporters in Michigan to watch for precinct-level delegates who may defect to a rival candidate during a contested convention.

“Are they a true Donald Trump supporter?” an email to supporters asks. “Many impostors that are actually aligned with the establishment will emerge from the woodwork and try to throw off the process.”

Another email to supporters and delegates details complicated parliamentary procedure strategies, even including how to topple the chair of the convention. It also instructs precinct-level delegates to record audio or video of their local conventions.

“If we are going to make credential claims, we must have proof and evidence,” the email reads. “Do not be intimidated by a bully chair, you have every right to record the caucus.”