Forty years ago, on June 4th, 1968, Robert Kennedy was shot in the head in a narrow room adjacent to the kitchen at the Ambassador Hotel in Los Angeles. He had just won the California primary election and was now the probable next President of the United States.

Yesterday, I awakened from a late-afternoon nap and switched on MSNBC for the day’s latest political news and saw –– as did many millions of Americans –– Hillary Clinton speak about the possible assassination of Barack Obama.

She and her campaign staff then tried several times to ‘explain’ what she said, although as Eugene Robinson pointed out what she in fact said admits of no such possibility. In law school we learned a few handy Latin legal terms, one of which was ‘res ipsa loquitur’. The thing speaks for itself.

Across the mass media and spreading through the internet are choruses of professed shock, disbelief, anger, and self-righteous idiocy, not limited by political party or ideology but sharing one unifying characteristic: denial.

Denial: that Clinton had in mind the possibility that Barack Obama would be assassinated.

Denial: that political candidates ever entertain such thoughts, nor discuss them with close advisers.

Denial: that discussion of political assassination has a ‘proper’ place in political discourse in the United States.

There are two salient facts here. One is that Clinton has certainly considered that her candidacy, having failed electorally, remains viable only if Obama dies. One would have to cling to a naivete bordering on the comatose to believe otherwise. She is not the only candidate ever to think such dark thoughts.

The second is that the prospective assassination of a political candidate in America is based in the even darker reality of our political life and history, not because we have been robbed of two Kennedys by crazed lone gunmen but because by this time we surely know that these murders were motivated by power, and carried out by people in a position to plan and execute them.

America in 2008 presents a political context notable for its similarity to 1968. Forty years ago, with a failed war and domestic unrest giving rise to a popular movement for change, there were three serious candidates for the presidency. These were Richard Nixon, Hubert Humphrey, and Robert Kennedy. (McCarthy’s candidacy was never a legitimate prospect; if necessary, I’ll explain that some other time). The forces which had executed John Kennedy were untroubled by Nixon and Humphrey, each of whom had long since whored themselves out. But Bob Kennedy was dangerous. Not only would he reverse America’s war policies, threatening the vast financial windfall being gathered by Brown & Root (precursor to KBR, which is today Halliburton), and the arms merchants, he had confided to his closest friends that he would go after the men who had killed his brother, and those people knew it.

In 2008, we are witnessing the first populist insurgency in 40 years in the candidacy of Senator Obama. His principal opponents, McCain and Clinton, are both creatures of the country’s ruling corporations and its military/security apparatus. Obama is therefore at risk. He knows it; his people know it; the media know it; Clinton and McCain know it.

The American people know it, too. Millions are aware of what actually happened forty years ago –– not the made-for-TV, officially-sanctioned fantasy –– and understand therefore that there are forces in the country who regard an Obama presidency as personally dangerous. This is not only a matter of political and economic power, the loss of jobs or the billions of dollars in graft currently being siphoned from the treasury through fraud and war profiteering. It is a matter of prison terms.

The reason the media don’t want to talk about assassination and the reason politicians, though they all think it, are not going to say so, is that what really happened in 1963, and again in 1968, has never been admitted, nor the perpetrators exposed or prosecuted. There has existed for forty years the worst conspiracy of all, the conspiracy of silence. It is the conspiracy of silence which makes possible further horrors, and it is the conspiracy of silence which makes of us all accessories both before and after the fact.

Hillary Clinton’s great crime is that, tired and running out of rationales, she blurted a reference to what no one is supposed to mention. Her ‘great crime’ is nothing in comparison with our own.