Overheard shortly after Barack Obama’s speech in Philadelphia: "He says he’s a Christian, but he was born a Muslim. Once a Muslim, always a Muslim. There’s only one thing you can do with a Muslim. Kill him."

Why does this give me such a sick feeling in the pit of my stomach? It isn’t as if I hadn’t heard this sort of thing before.

"The more they die the better." Hein-rich Himmler, Nazi chief of police, speaking of the Jews in Germany, 1939.

"The only good Indian is a dead Indian." Gen. Philip Sheridan, the Union officer in charge of the Oklahoma Indian Territory in 1869.

"Kill them all." Instructions from the Papal Legate to Crusaders invading Beziers in 1209. The city was held by heretics, but was home to many Christians.

But this isn’t Hitler’s Germany, or the Western territories or the Crusades. This is North Georgia in the year 2008. Apparently, we haven’t learned a thing. If only, the thinking goes, we could get rid of the Jews, the Indians, the Muslims, illegal immigrants — take your choice — our problems would be solved. The man overheard making the remark about killing Muslims was probably a good family man, even a good church member. His friends might say that he was hotheaded or outspoken, but that he doesn’t mean half of what he says. He’s just an ordinary guy and shouldn’t be taken seriously.

That’s just the point. He probably is an ordinary guy. Why get upset? After all, he doesn’t even have his facts straight. Barack Obama’s Kenyan father was an atheist, and his parents separated when he was 2. Obama was raised by his maternal grandparents, who were both Christian and white. He spent some of his early years in a Catholic school.

I am sickened by this ordinary guy’s remarks because they are ordinary. How often have you heard someone explode, "I could kill that guy?" Angered by some personal offense, an individual lashes out, but the target of his anger is usually someone essentially like himself, a neighbor, a family member or a co-worker. We understand the man is just letting off steam, and we don’t take these remarks seriously.

But when one’s anger is directed at a racial or religious group, when someone suggests that everyone in that group should be eliminated, it’s different. The target group has just been defined as essentially less valuable, less human than the speaker. This kind of remark is dangerous, and it should be taken seriously.

Hitler didn’t start out gassing Jews. He started by suggesting that Jews were not true Germans, not good neighbors, not really human in the way the Aryan population was. Germany, in fact all of Europe, would be better off without them. When enough people repeated this, it was but a small step to the gas chambers.

Am I blowing a casual remark overheard at a lunch counter all out of proportion? I don’t think so. Nobody looked shocked. Nobody reacted. If it had been a teenage boy and he’d said someone ought to kill all the teachers at the local high school, I suspect there would have been a reaction. But this remark was made about a political candidate, probably one not well-liked in that particular diner. Thus the target was "fair game" and the remark accepted as of little consequence.

My point is this: What we say is not divorced from what we think, and what we think colors how we act. This particular individual is not likely to go out and shoot a Muslim, but he made it clear that if someone else pulled the trigger, he wouldn’t be sorry. Furthermore, the inference is that if some Muslim could shoot a Christian and get away with it, the Muslim would probably do it.

This is a dangerous piece of nonsense. It sets one group of Americans against another, and this is exactly the kind of thinking that can destroy a democracy. There are between 4 and 6 million Muslims in the U.S. today. The number of Native Americans, or Indians, is approximately the same, the number of Jews slightly larger.

Mexicans seems to be the target of choice these days, but close to 10 million Mexican-born individuals are now U.S. citizens. Our nation has always been a melting pot. The individual who would set one American against another undermines the security of all.