Have the mainstream media been fair in their coverage of Barack Obama's associations with radical elements of the American left? Here is a useful guide for answering that question: What if John McCain had similar associations with the radical right?

Barack Obama's political career was launched in the home of William Ayers, a left-wing terrorist who spent the 1970s running from the FBI. Ayers was a co-founder of the Weather Underground, a domestic terror organization that bombed the Pentagon, police departments and the homes of government officials. In a 2001 New York Times interview, Ayers said, "I don't regret setting bombs. I feel we didn't do enough."

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Not only did Ayers host the house party that launched Obama's political career, but he and Obama served on a nonprofit board together for three years.

Imagine if John McCain's career had been launched at the home of a right-wing terrorist such as Timothy McVeigh. Do you think the media would be shrugging their shoulders?

Barack Obama taught classes for the Association of Community Organizations for Reform Now, or ACORN, represented the group in a lawsuit against the state of Illinois and paid it for organizing work during his presidential campaign. ACORN's Nevada offices were just raided. The state alleges extensive voter fraud.

Imagine if John McCain were closely associated with a right-wing group that state officials say was actively committing widespread voter fraud running up to this election. Would the media ignore it?

Barack Obama spent two decades as a member of a church in which the pastor preached racial separatism and condemned America. If John McCain spent two decades in a church with a right-wing pastor who preached a version of white supremacy and routinely condemned America, would the media suggest that the tie was no reflection on McCain's own thoughts or ideology?

Barack Obama is not Bill Ayers or Jeremiah Wright. He doesn't look or sound like that kind of left-wing radical. But his voting record -- National Journal named him the most liberal member of the U.S. Senate last year, ahead of Ted Kennedy and Socialist Bernie Sanders -- and his close associations with the radical left suggest that ideologically he is as far left as a politician in America can get and have any hope of getting elected. And they suggest that his beliefs are far more radical than the moderate image he presents in public.

But Barack Obama is not a Republican. And therefore his ties to fringe elements in his party are ignored and discounted by a fawning media that would leave no stone unturned were the candidate with radical associations named John McCain.