The images appeared on Twitter in late 2016 just as the presidential campaign was entering its final stretch. Some featured the message “vote for Hillary” and the phrases “avoid the line” and “vote from home.”
Aimed at Democratic voters, and sometimes singling out Black people, the messages were actually intended to help Donald J. Trump, not Hillary Clinton. The goal, federal prosecutors said, was to suppress votes for Mrs. Clinton by persuading her supporters to falsely believe they could cast presidential ballots by text message.
The misinformation campaign was carried out by a group of conspirators, prosecutors said, including a man in his 20s who called himself Ricky Vaughn. On Monday he went on trial in Federal District Court in Brooklyn under his real name, Douglass Mackey, after being charged with conspiring to spread misinformation designed to deprive others of their right to vote.
“The defendant, Douglass Mackey, tried to steal people’s right to vote,” a prosecutor, Turner Buford, told jurors Monday morning during his opening statement. “He did it by spreading a fraud.”
A few minutes later, a defense lawyer, Andrew J. Frisch, said that Mr. Mackey, “a staunch political conservative,” would testify in his own defense. Mr. Frisch added that his client had been trying only to attract attention to himself by posting memes, not carry out a clandestine conspiracy.
“Mr. Mackey did not share these memes as some sort of grand plan,” he said, adding that it was “not a crime to vigorously support your candidate of choice.”
Prosecutors have said that Mr. Mackey, who went to Middlebury College in Vermont and said he lived on the Upper East Side of Manhattan, used hashtags and memes as part of his deception and outlined his strategies publicly on Twitter and with co-conspirators in private Twitter group chats.