Secret Service fears for Obama

• Protecting Barack Obama has presented the US secret service with the greatest challenge in its history, not least because the real threat comes from right wing extremist groups operating inside America. In just over a year, the number of groups has risen from 149 to 512

Oklahoma bomber

“As they dig into the subject, going down into the funnel, they start to lose connection with the social networks around them that keep them tied to normality. Down, down they go, and eventually out the other end of the funnel emerges the Oklahoma bomber, Timothy McVeigh, who says, ‘Our country is under attack, I must do something about it.’”

It’s the thought that some may be emerging from the end of the funnel at this politically charged moment, McAdam says, that bothers him so, and makes him think that “violence against President Obama is a real concern”.

McVeigh, executed in June 2001, is a name that crops up frequently among the extremism monitors. It comes up again when Mark Potok gives his last word on the threat to Barack Obama.

The white supremacists and anti-government militia who are out to get the president should not be underestimated, he says. “These groups aren’t al-Qaeda. Most of them look vastly more bumbling than effective.” But then he adds: “It only takes one to get through. Timothy McVeigh taught us that.”

Copyright Guardian News & Media Ltd 2010