Journalists have been known to seek the best angle.
But it was after Obama's speech that O'Reilly threw some elbows. And not so figuratively either.
Obama staffer Marvin Nicholson, a personal aide always at Obama's side during rope line handshakes, said O'Reilly yelled at him to get out of the way of his cameraman's shot. Nicholson said O'Reilly came around the waist-high barricade separating Obama from well-wishers.
"Then he grabbed me with both of his arms and tried to push me out of the way," Nicholson said after the campaign agreed to make him available to reporters.
A Fox News spokesman did not immediately respond to e-mail and phone messages.
The scene was hard to miss. O'Reilly is about 6-feet-5-inches tall. Nicholson is 6-feet-8-inches tall.
"I told him, 'Sir, I would appreciate it if you wouldn't shove me anymore.'
"He called me 'low class.' He was pretty upset."
Secret Service agents assigned to protect Obama ordered O'Reilly back behind the barricade. At that point Obama approached him and extended his hand.
O'Reilly, Nicholson recounted, "said the senator was great and that he would love to have him on the show."
Nicholson, a veteran of political campaigns, worked as Sen. John Kerry's personal aide in the 2004 presidential campaign, acquiring the nickname "Chief of Stuff."
"I've never seen a member of the press lay hands on a staffer before," he said.
Democrats, prodded by liberal activists who argue Fox News is biased, have been avoiding the cable news network. Fox had to cancel a scheduled Democratic debate after the candidates refused to participate.
So how did Obama react to O'Reilly's entreaty?
"The senator said he would think about going to the show after the primaries," Nicholson said.
O'Reilly later showed up at a Hillary Rodham Clinton event in Penacock, N.H., and was acknowledged by the candidate. He stood in the audience and urged an audience member to ask the New York senator and former first lady about her plan to remove troops from Iraq.
When the audience began booing, Clinton said, "No, no, no. He gets at least some credit for being here."
