President Obama's stimulus package which is about to be passed by the American Congress includes a "buy American" clause which essentially will make it impossible for Canadain goods (and those of other countires) to be used in any project funded by the goverment.
In reality, that's impossible. We don't make anything anymore and buy everything. The most it can do is make the project coordinating company an American company. I would say it is just a political token statement.
Artemis