Jonah Goldberg predicted it. Glen Reynolds nodded in sage assent. The campaign of Barack Obama will inevitably lead to violence on the campaign trail. " I seriously think certain segments of American political life will become completely unhinged," said Goldberg. We scoffed. And yet — it has come to pass:

Bombastic Fox News host Bill O’Reilly got into a confrontation with an Obama aide after O’Reilly started screaming at him as he tried to get Barack Obama’s attention following a rally here.

The incident was triggered when O’Reilly–with a Fox News crew shooting–was screaming at Obama National Trip Director Marvin Nicholson “Move” so he could get Obama’s attention, according to several eyewitnesses. “O’Reilly was yelling at him, yelling at his face,” a photographer shooting the scene said.

O’Reilly grabbed Nicholson’s arm, said “move” and shoved him, another eyewitness said. Nicholson, who is 6′8 said O”Reilly called him “low class.”

Secret Service agents came after O’Reilly pushed Nicholson and the agents flanked O’Reily.

Obama had his back turned at this point and did not see any of this. O’Reilly yelled “sir” at Obama and Obama walked over, not aware of what happened and told him he had an overflow crowd to visit. According to the time code from a photographer shooting the two, Obama and O’Reilly talked about 12 seconds near 11:45 a.m. eastern time.

The situation took place near a basketball hoop in the gym at Nashua North High School where Obama just addressed a jammed rally.

There is evidently no video tape of the kerfuffle, but a photographer from Polaris reportedly got some stills.

I guess we’ll get to see who comes "unhinged."