The short, pudgy, sallow-faced man with the receding hair pointed to the blackboard. Rule One contained three words: "Destroy Your Opponent."

He told the audience: "If you do not deflate the opposition candidate before your own campaign gets started, the odds are that you are going to be doomed to defeat."

In a campaign where Donald Trump has labelled Hillary Clinton a crook, mused about her assassination and revelled at the chants of "Lock her up" at his rallies, Murray Chotiner's words have perhaps lost their ability to shock. But, as America prepared to re-elect Dwight Eisenhower 60 years ago, Chotiner's campaign class had sufficient shock value for the Democrats to republish it in order to discredit him.

While Trump's presence may well ensure that this year's US presidential election is one of the dirtiest ever, there is, of course, nothing new about negative campaigning. In 1828, Andrew Jackson's opponents labelled his mother "a common prostitute" and his wife an "adultress" and "bigamist".

Nonetheless, the middle of the last century saw the emergence of a number of interrelated factors - the growth of the role of television and advertising; the opening-up of the political process; and the decline of parties and rise of candidate-centred politics - which would fundamentally reshape the manner in which campaigns were conducted.

As with so many other fashions, California set the pace and Chotiner - a young lawyer and PR man - would be one of the foremost trend-setters. Like Richard Nixon, the man with whom his career would become inextricably intertwined, Chotiner's start in life was inauspicious. Born into a Jewish family in Pittsburgh, his father was a cigar maker, who moved the family to California to run a chain of cinemas but then abandoned his wife and sons.

Murray was bright and precocious - at the age of 20, he became the youngest person to graduate from Los Angeles' Southwestern College of Law. He soon became immersed in Republican politics, working in Herbert Hoover's presidential campaign in 1932 and enlisting in California political races.

Already, Chotiner's ruthless political street-fighting was getting him noticed - not always to his advantage. Having seen his Machiavellian tactics at work, California governor Earl Warren - later a highly respected Chief Justice of the US Supreme Court - barred Chotiner from his 1946 re-election campaign. However, Nixon, running for Congress for the first time, had no such qualms. Although primarily consumed by helping a prominent Republican Senator win re-election - with Cold War tensions rising, the budding political strategist came up with the slogan "We Will Not Surrender", which hinted that his opponent would - Chotiner helped guide Nixon to an unexpected victory.

He had urged his candidate to run a "high-risk campaign". By the end of it, Nixon's opponent, Congressman Jerry Voorhis, had been comprehensively, albeit falsely, painted as a Communist fellow-traveller; funded by, and a tool of, the far left.

Four years later, Nixon had Chotiner's undivided attention when he ran for the US Senate. His opponent was Helen Gahagan Douglas, a liberal Congresswoman and wife of the actor Melvyn Douglas. Nixon promised a "fighting, rocking, socking campaign" and his campaign manager was determined to hold him to that pledge.

"It would be a colossal blunder to revert to [a] conventional campaign," Chotiner wrote to him.

Once again, the politics of personal destruction would form the core of the campaign. Most notorious was the so-called "pink sheet": a flyer misleadingly comparing Douglas's voting record to that of a New York congressman who was well-known for his Communist sympathies. Chotiner ordered 500,000 copies printed on pink paper. "She's pink right down to her underwear," chimed Nixon.

They were trailing new, now highly familiar, campaign techniques, purchasing the first crude television ads for the still-small Los Angeles market and employing companies to make anonymous phone calls. "Did you know Mrs Douglas is a communist," the callers asked. On election day, the "Pink Lady" went down to a landslide defeat.

The campaign, one history later suggested, "set the tone for increasingly negative and personal politics in America", elevating the art of character assassination to national prominence and turning Chotiner into one of the country's best-known political operators.

Chotiner affected modesty: "All we did was publish her voting record." His private view - "nice guys and sissies don't win elections" - was rather more accurate. He may not, the journalist Lou Cannon argued, have invented "the cult of the smear" but he had refined it for the television age.

"An attack," Chotiner advised Nixon, "always makes more news than defence." Over the next 20 years, it was a lesson than Nixon never forgot, and few American political consultants would deny today.

Allegations of antisemitism plagued Nixon long before the publication of taped White House conversations revealed the president's obsession with "disloyal" Jews supposedly seeking to undermine his administration. With good reason: in 1950, Nixon publicly disavowed the support of one far-right campaigner, who urged voters not to "send to the Senate the wife of a Jew".

That disavowal, however, didn't stop Nixon from occasionally labelling Douglas "Helen Hesselberg"- Melvyn Douglas's original surname - before correcting himself as if it were an inadvertent slip. But, when Nixon faced accusations of antisemitism after Eisenhower picked him for the ticket in 1952, Chotiner was on hand to help. His Jewish campaign manager secured a seal of approval for his boss from the Anti-Defamation League, which Chotiner made use of to answer letters to the campaign headquarters from voters concerned about the charges.

Allegations of influence-peddling in 1956, as well as suggestions that he was, in the words of one lurid headline, "Dick Nixon's Secret Link To The Underworld" meant that Chotiner increasingly operated behind the scenes, although the truth remained murky.

He remained a master of the dark arts for which Nixon's campaigns would be renowned. In 1968 and 1972, for instance, he was responsible for planting spies posing as reporters who fed back intelligence from the campaigns of their Democrat opponents.

However, Chotiner was smart enough to foresee danger on the horizon. Standing outside the offices of the president's re-election campaign in 1972, he warned one aide: "They are going to get in trouble." When Chotiner died in a car accident 18 months later, Nixon's days in the White House were already numbered. Another of the former president's Jewish advisers, the rather more cerebral Leonard Garment, suggested that Chotiner was "a hardheaded exponent of the campaign philosophy that politics is war". Over the next three months, that philosophy will become abundantly and increasingly evident.