You’re watching "The O'Reilly Factor,” Fox News Channel's popular interview show.  The host is commenting acidly on the presidential campaign.  To illustrate a point, he airs some video of Al Gore addressing the Democratic convention in Los Angeles.  And as you watch, amazed, the words "Snipers Wanted" appear on the screen as Gore speaks.
    It never happened, of course.  But imagine the reaction if it had.
    If O'Reilly ever pulled such a stunt, he would be pilloried from coast to coast.  Editorials would sear him for joking about murder.  Democrats would blast the "sick right-wing mentality" that thinks killing the vice president is humorous.  Talk shows would seethe.  The Federal Communications Commission would investigate.  And Fox News, flooded with petitions demanding O'Reilly's head, would be forced to take him off the air.
    That's the script, more or less, when well-known conservatives aim vicious insults and hateful slurs at liberals.  But when the venom moves in the other direction - when it's a conservative getting smeared - the indignation meter barely flutters.
    Which is why there was no explosion over "Snipers Wanted."
    The truth is, it did happen - but not on Fox News and not with an image of Al Gore.  It was Craig Kilborn, host of CBS's "Late Late Show," who put out the call for snipers while showing footage of George W. Bush at the GOP convention.  Eventually, CBS apologized, mumbling something about the joke being "inappropriate and regrettable" - and that was the end of it.  No seething, no petitions, nobody taken off the air.
    As each year draws to a close, I take a look at this persistent double standard.  Each year, sad to say, there is no shortage of illustrations.  Y2K was no exception.
    Bush didn't realize the microphone was live when he described New York Times reporter Adam Clymer as a "major league asshole," and got pummelled for his crudity.  Dan Rather, for instance, scolded him for "meanness," "nastiness," and using "gutter language." But when Jesse Jackson accused Bush of using "Nazi tactics" to win the election, neither Rather nor any of his colleagues lifted an eyebrow.
    Granted, it's not nice to use the A-word.  But it's not nearly as vile as comparing your political opponents to acolytes of Adolf Hitler.  Yet liberals routinely liken Republicans and conservatives to mass-murdering totalitarians, and no one objects.
    The platform of the Texas Republican Party, Bill Clinton sneered in June, "was so bad that you could get rid of every fascist tract in your library if you just had a copy" of it.  Joe Gellar, the Democratic Party chairman in Miami-Dade County, fumed that out-of-town Republicans protesting the ballot recounts were engaging in "brownshirt tactics."
    And for those too dense to grasp the point - conservatives are the moral equals of the men who ran Auschwitz - filmmaker Michael Moore spelled it out.
    "There are tens of thousands of people who lived through (the Holocaust), escaped the ovens, and are now living out their final years in South Florida," he wrote in demanding a new vote in Palm Beach County. "Sixty-two years ago tonight, the. . . German government sent goon squads throughout the country to trash and burn the homes, stores, and temples of its Jewish citizens.  Seven years and six million slaughtered lives later, the Jewish people of Europe were virtually extinct.  A few survived.  I will not allow those who survived to ... be abused again."
    Anticonservative hate speech was plentiful in 2000.  None of it provoked an outcry from the national media.  Some lowlights:
    Gay activist Dan Savage boasted on Salon.com of his efforts to infect Gary Bauer With flu.  In his New York Press column, Alexander Cockburn suggested "dropping a tactical nuclear weapon on the Cuban section of Miami." A sickening TV spot by the NAACP showed a pickup truck dragging a chain and accused Bush of having "killed" James Byrd "all over again" when he opposed a change in the Texas hate crimes law.
    But for pure vitriol, nothing matched the eruption of former Clinton aide Paul Begala, who wrote on MSNBC.com about the map with color-coded election returns that showed a sea of red for Bush with small blotches of blue for Gore.
    "But if you look closely at that map you see a more complex picture.  You see the state where James Byrd was lynched-dragged behind a pickup truck until his body came apart - it's red.  You see the state where Matthew Shepard was crucified ... for the crime of being gay - it's red.  You see the state where right-wing extremists blew up a federal office building and murdered scores of federal employees: red.  The state where an Army private thought to be gay was bludgeoned to death with a baseball bat ... and the state where Bob Jones University spews its anti-Catholic bigotry: they're all red, too."
    Ugly, nasty stuff.  A conservative who talked this way about liberals would be lacerated.  When will liberals stop talking this way about conservatives?

Jeff Jacoby is a columnist for The Boston Globe.  His e-mail address is jacoby@globe.com.