"I don't think he's American, personally," he said Thursday in a video that's been posted on YouTube. "You know, if you're not willing to produce an original certificate like a birth certificate, then you've got something to hide."
The mayor was echoing complaints made by some tea party activists and so-called birthers who doubt the president is qualified to hold his office. Though state officials in Hawaii say vital records there confirm Obama was born there, birthers say the president has never proven his citizenship.
A spokesman for the Illinois Democratic Party said he was surprised to still be responding to questions about Obama's legitimacy.
"Most rational people have discarded that question years ago," Steve Brown said.
A Champaign County board member said he was "flabbergasted" and is calling for Schweighart's resignation after seeing the video of the remarks.
"I think his willful ignorance of the facts and his bias against the president of the United States makes him unable to run the city of Champaign," Al Kurtz said Friday, according to the News-Gazette.
Schweighart dismissed Kurtz's comment.
"That's his opinion," he said.
Schweighart said the man who videotaped him appeared to be part of a student group from the University of Illinois who attended the rally in opposition to the tea party.
The mayor said he doesn't know Obama, though years ago he shared a table with him at a Champaign event where Obama spoke. Schweighart said he had no particular awareness of Obama as a politician — much less concern about him — before the former senator from Illinois became president.
But Schweighart, who was a Champaign police officer for 32 years, said he shares many of the tea party's concerns about the president's health care plan and other issues.
"It's just worrisome that the government is going to be running everything," he said.
The president's birth certificate has been closely examined and concluded to be authentic.