If any good can come of the horror in Tucson, it will be that this becomes a McKinley moment for Sarah Palin and her chief spokesman, Glenn Beck.

One hundred and ten years ago, during another low point in the nation's political discourse, newspapers owned by William Randolph Hearst - who was angling for a presidential run in 1904 - published a pair of columns fantasizing about violence against President William McKinley.

Columnist Ambrose Bierce wrote that a bullet "is speeding here to stretch McKinley on his bier." Next, an unsigned column widely attributed to Hearst editor Arthur Brisbane declared: "If bad institutions and bad men can be got rid of only by killing, then the killing must be done." Six months later, a deranged man named Leon Czolgosz assassinated McKinley.

The killer claimed he was inspired by an anarchist, not by Hearst - but that didn't stop opponents from falsely claiming that Czolgosz had a copy of Hearst's New York Journal in his pocket when he did the deed. Secretary of State Elihu Root later accused Hearst of driving the "weak and excitable brain of Czolgosz" to murder. The outcry against Hearst's incitement - there were boycotts and a burning in effigy - dashed his presidential ambitions.

A similar, and long overdue, outcry has followed the Tucson killings. Sheriff Clarence Dupnik, who blamed the "vitriol we hear inflaming the American public" for the massacre, mentioned Palin by name and generally denounced conservative TV and radio commentary. Some in the media have fingered Beck, too.

While the accusations sometimes go too far - there's no evidence that either Palin or Beck inspired the Tucson suspect - the heat is well deserved. Both are finally being held to account for recklessly playing with violent images in a way that is bound to incite the unstable. In Beck's case, as I reported last year, it already has - repeatedly.

Palin's now-famous offense was her tweet last March telling conservatives: "Don't Retreat, Instead - RELOAD!" The tweet referred people to her Facebook "target" map showing the districts of Gabrielle Giffords and other House Democrats in a rifle's cross hairs.

Palin has been uncharacteristically quiet since Saturday's slayings. She posted a brief Facebook message offering condolences, and an aide even tried to claim that the crosshairs, which Palin had called a "bull's-eye," were really "surveyors' symbols."

The real defense of Palin was left to Beck. On his radio show Monday, he read aloud an e-mail she had sent him: "I hate violence," it said. "Our children will not have peace if politicos just capitalize on this."

Beck furiously defended Palin, and himself, during his three-hour broadcast. "We are not going to play defense at all!" he vowed, rallying his followers: "Offense!" Beck denounced media "fatheads" and said Sheriff Dupnik has "no facts." The real source of violent rhetoric comes from the left, he said - particularly liberal academic Frances Piven, who called for an uprising against the government. In 1966.

Liberals have indeed stirred violence over the years - as recently as two years ago, I argued that the left's rhetoric was more vitriolic - but at the moment the "Second Amendment remedies" are coming mostly from the right, and from none more than Beck.

On Monday, Beck denounced violence and said that he and Palin aren't to blame for what a "madman" does. "Intent matters," Beck said, and he isn't "looking to incite violence." But it's not that Beck and Palin are advocating violence. The danger is that unbalanced characters, attracted by the violent talk, take literally the metaphoric call to arms.

Among Beck's contributions to the discourse: "Somebody has a gun to your head.. . . You're going to have to shoot them in the head.. . . I don't know how I don't get a bullet in my head some day. . . . Shoot me in the head if you try to change our government." Beck, who has fantasized on the air about killing political opponents, has told his followers to "Grab a torch" and to "Drive a stake through the heart of the bloodsuckers."

Have we finally tired of such words? Last week, the New York Daily News reported that AM talk-radio station WOR was dropping Beck's show because of low ratings.

And that was before the McKinley moment. While Republican congressional leaders joined President Obama in Monday morning's moment of silence, Beck mocked it as an Obama photo-op. His show was on commercial break during the silence, and when he returned to the air, he said: "It wasn't silent in Washington - it was just the sound of cameras being snapped."

Maybe Beck and Palin will be good enough to show us what a real moment of silence is - by having themselves a nice long one.

danamilbank@washpost.com