Sarah Palin has blood on her hands," said the New York Daily News on Jan. 9, the day after Rep Gabrielle Giffords, D-Ariz., was gravely wounded in Tucson, 12 others were injured, and six others were killed. Why? Months ago, she put on her Web site a map of the 2010 midterms in which Giffords' district was placed in cross hairs, a commonplace sort of political image, and one the killer neither heard of nor saw.

The idea is that words written somewhere become known at once to criminals everywhere -- and, even if no direct linkage is ever established, can cause a crime anyhow, as part of a "climate of hate."

The "climate of hate" is a miasma formed by the vapors of words one disagrees with, these days quite often from blogs or talk radio. The problem is that these climates are sometimes deceptive, and the link between word and deed is unclear.

"Climates of hate" did exist in 1865 and 1968, when President Abraham Lincoln and the Rev. Martin Luther King Jr. were shot and murdered, but elsewhere the linkage is dim. No climates of hate existed in 1881 or 1901, when Presidents James Garfield and William McKinley were murdered; in 1912, when President Theodore Roosevelt was shot at and wounded, or in 1933, when President Franklin D. Roosevelt was shot at, and missed.

A climate of hate rose from the right wing in Dallas, but a communist shot and murdered President John F. Kennedy. Robert Kennedy aroused passions about many things, but the Middle East was not one of them.

President Ronald Reagan was demonized by the left, but was shot by a man who wished to impress Jodie Foster. President Gerald Ford was the least controversial man who ever was president, but he was shot at twice in his very short tenure, while President George W. Bush and President Bill Clinton, who roused vast gales of loathing, passed eight years apiece without incident.

The hate that makes people protest, complain, and draw angry posters is one thing, but the hate that leads them to kill seems a whole other story. Which brings us to point No. 2.

It may be true that words can lead people to murder, but it helps if they're words killers hear. Apparently the killer in Tucson listened to none of them. "He didn't watch TV," a friend of his tells us. "He disliked the news. He didn't listen to political radio. He didn't take sides."

Those who do listen take the words in the spirit in which they are meant. Millions of people visited Palin's Web site (and similar ones set up by the Democrats) and took the violent step of sending money to candidates. Liberals clucked at the Tea Partiers' signs, and their talk, and the guns that they carried, and prophesied bloodbaths.

And what did they do? They organized, marched, ran candidates in elections, and took defeat in good grace when they lost.

But sometimes there are times when words lead to violence or to threats of it, and one of them happened last week.

Eric Fuller, one of those wounded in the parking lot rampage, turned up at a meeting convened by ABC News and threatened the head of the local Tea Party, screaming "Trent Humphries, you're dead!" What could have moved him, except claims by the New York Times, Daily News, Chris Matthews and others that the Tea Party and Palin had "blood on their hands" for the rampage?

Have threats to Tea Partiers and Palin spiked upward since these dogs began barking? Of course.

Would they have "blood on their hands" if anything happened? You betcha.

Would this disturb them? Who knows?

Examiner Columnist Noemie Emery is contributing editor to the Weekly Standard and author of "Great Expectations: The Troubled Lives of Political Families."