When you hear anyone today compare what is happening in the U.S. with Nazi Germany, you can safely conclude that person is a hyperbolic fool who has run out of valid arguments.
The comparisons are fatally flawed and, worse, dilute the historical significance of the Holocaust.
The latest example came Jan. 19 when a little-known congressman from Tennessee stood on the floor of the U.S. House and compared the arguments of Republicans against health care reform to the work of Nazi Propaganda Minister Joseph Goebbels.
Rep. Steve Cohen's comments echoed an accusation he made in April comparing the origins of the tea party movement to those of the KKK.
As our political rhetoric has heated up over the past decade, so has the frequency of over-the-top Hitler and Nazi comparisons.
In 1989, Mike Godwin made a revealing observation: "As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches."
This statement eventually became known as Godwin's Law.
Unfortunately, as the quality of political discussion has deteriorated in recent years, the phony comparisons have migrated to cable TV and talk radio.
Last week, a coalition of rabbis asked Fox News and its hosts to stop using comparisons to the Holocaust.
Last November, Fox News President Roger Ailes called NPR executives "Nazis" for firing commentator Juan Williams. Ailes later apologized, explaining that he was simply angry.
But the Nazi comparisons have also been repeatedly used by conservative commentators like Rush Limbaugh, Bill O'Reilly and Glenn Beck, as well as former liberal talk-show host Keith Olbermann.
As our political debate becomes more impassioned, the temptation to resort to Hitler and Nazi comparisons seems to grow.
Playing the Nazi card may be appealing, but it suffers from a basic logical flaw.
Almost anything that happens today can be compared to something that happened in Nazi Germany.
For instance, Nazis believed in social welfare programs for workers. Therefore, social welfare programs lead to horrific excesses of Nazism.
In reality, there are many countries that have social welfare programs and even national health care systems that have not resorted to the crimes of the Nazis.
It is a classic guilt-by-association fallacy. Just because something shares a similarity with something else does not prove it is or will become that thing.
Hitler was also a dog owner, yet few people would argue dog ownership leads to genocide.
But the other reason to avoid Hitler comparisons is that they soften the historical reality of Nazism and its murderous program of killing Jews, gypsies, gays, Poles, Soviet civilians, the disabled and others they deemed unworthy.
Scholars estimate about 12 million people perished during the Holocaust, more than six million of them Jews killed with factory-like efficiency.
While we may all disagree with our political foes, we should be able to agree that none of our political leaders or their proposed programs bear even the slightest resemblance to that.