What does it say about the President of the United States when the man whose living room he launched his political career from isn’t even allowed to enter Canada?

(National Post) — Former American radical Bill Ayers has once again been barred from entering Canada.

Mr. Ayers was scheduled to deliver a keynote address at the Worldview Conference on Media and Higher Education this Thursday in Toronto. Conference organizers say Mr. Ayer’s refused entry should “should raise red flags for citizens concerned with free and open debate.”

“Bill Ayers is a respected academic, and in no way a threat to the peace and security of Canada. There is no reason why he should be kept out,” said Mark Langer, President of the Ontario Confederation of University Faculty Associations (OCUFA), who is hosting the event.

Mr. Ayers was barred from entering Canada in 2009 after touching down at Toronto City Centre Airport. At the time, he said he had entered Canada dozens of time before without incident.

Mr. Ayers has hired Canadian and American lawyers in unsuccessful attempts to lobby the Canadian Border Services Agency for passage into the country. Advised by his lawyers that he would likely be held at the border, he did not attempt a crossing this time around.

In the late 1960s, Mr. Ayers co-founded the Weather Underground, a radical group that collaborated on a series of bombings aimed at banks, monuments and government buildings, including the Pentagon and US capitol.