Please excuse a little hyperbole. Everything is relative.
Having lived in Canada, I can tell you that while it certainly isn't the Soviet Union, it also isn't the USA.
Hyperbole excused. However, I think it's important to avoid it.
These days it's mostly the left-wing which is failing to draw relevant distinctions. For someone who has known and loved real concentration camp survivors, it's annoying (to put it mildly) to hear Bush compared with Stalin.
Based on something she said, I asked a participant on some European blog, "So you think Stalin was a pretty nice guy?" "Well," she says, "I don't really approve of his policies regarding gays, but other than that, I feel he was pretty okay."
"Well, ya know," I say. "I probably don't agree with his policies regarding gays either. But I find the fact that he tortured and murdered 20,000,000 people without trial rather more objectionable." "Lies, all lies," she says. "Well, ya know," says I, "it's well documented in the form of billions of personal letters, it's engraved into the minds of an entire nation whose Papas and Dyadya Mishas disappeared in the night... History will know the truth even if you don't. If you lie to yourself about the diagnosis, you're likely to prescribe the wrong medicine."
However, it's no excuse for the other side to do the same sort of thing. It so easily gets out of hand, as Revel points out. Words have power, and exaggerations expressed gain a kind of force of their own.
So as long as one is in the right, let him/her at least state the simple truth without embellishment. That's my opinion anyhow.
So Bush is not Stalin. Republicans are not Baathists. And Canada is not the USSR.