I agree that we're headed in the wrong direction, and I'm not a Bush fan, but this has been happening for a while. Naturalist Farley Mowat, one of Canada's great writers ("Never Cry Wolf"), was refused entry in the 1980s ... allegedly because he disagreed with cruise missiles (I've yet to meet a Canadian who enjoyed that period where American cruise missiles flew over Canadian territory). Hey, even Jack London had some questionable politics, but he still wrote a good yarn...

This is the ACLU's pithy take on it - http://www.aclu.org/SafeandFree/details/mowat.html - if you read through some of the other examples, some are rather surprising, such as Pierre Trudeau's exclusion in the 1950s. (Trudeau later became... wait for it... Prime Minister of Canada... a bilingual powerhouse who was hardly "subversive".)