I was always given the impression that the only difference between Tancredo and other conservatives is he's more strong on anti-immigration then everyone else, but other wise, all of his views are textbook mainstream conservative, i.e. lower taxes, free trade, reduce spending, and none of the populist economics.
Is that the case, because then, he could, on the minimum pull the election to the right, if still not be viable (I just don't think congressmen can get elected president in this day and age).