Margaret Thatcher was not the first to leverage the political power of the tabloid press, but – as with many things – she did it bigger and she did it best. In 1979, the year she came to power, the Observer described the Sun as "Mrs Thatcher’s missionary outpost to the working-class voter." By the time she left office a decade later, the Sunday Telegraph was willing to accept that, "the support of The Sun can make or break the fortunes of the Tory Party."

Every subsequent Prime Minister has had to come to terms with this doubled-edged aspect of Thatcher’s legacy. The closeness Thatcher cultivated with the tabloid press was a powerful weapon for any successor to inherit – but it came with a dangerous degree of vulnerability to an ever-mightier media empire. In this respect, the Leveson inquiry may prove to be the final reckoning in a saga that has been running for over 30 years.

The relationship between Thatcher and the tabloid press was authentic in a way that none of her successors – not even Blair – were ever able to emulate. Their natural affinity grew out of a shared and unabashed populism that flourished in a decade set up to reward populism like no other. Britain in the 1980s was a society ill at ease with itself. Despite the much-heralded "revolution" in social attitudes brought on by the sixties, the vast majority of the British public regarded the sexual liberation movements and "permissive" reforms of previous decades as the work of a remote political and intellectual elite. As the Sun proclaimed as late as 1994, "It doesn’t bother MPs that a consistent 75% of the British people want vicious killers to be hanged. It doesn’t impress them that most of us feel deeply uneasy with condoning acts of teenage homosexuality. Parliamentarians prefer to rely on their own consciences."

Like the reassuring rhetoric of the tabloid press, Thatcherite policy deftly channelled popular suspicion of these elites and the permissive values they condoned. Section 28 famously banned the ‘promotion’ of homosexuality in schools as a "pretended family relationship", in stark contrast to the sexual normalcy and nuclear family structures that would restore the nation to moral health. It managed to present homosexuality as a kind of Politically Transmitted Disease carried by the ‘loony left’, and by so doing, imbued the moral backlash against the gay rights movement with a sense of national urgency.

Perhaps the most ingenious of all Tory constructs, the "loony left" furnished the tabloids with a rich and never-ending seam of entertaining stories: in the mid-1980s it was reported that Labour-controlled local authorities had banned the nursery rhyme "Baa baa black sheep" and black dustbin liners as racist. Moreover, in its repetitive and unrelenting association of the left with unpopular permissive causes, this tabloid trope carried the Conservative message beyond the traditional Tory heartlands, and into the new, remoter electoral provinces of the Murdoch empire.

Later Tory leaders have all played to these resonances in one way or another. Particularly when there is political capital to be gained from a wider sense of social anxiety, Conservative politicians have a habit of lapsing into moral hyperbole. Just as Thatcher responded to popular anxiety about permissive reform, David Cameron (with the help of the Sun) built his 2010 election campaign around the motif of "Broken Britain", and John Major produced his ill-fated "Back to Basics" campaign in the wake of Black Wednesday and the murder of Jamie Bulger. Upbraiding a "broken" society and urging national regeneration through stronger family life has proven to be an effective – and cheap – way to reap mass support at times of social unease or moral panic.

Thatcher created a political culture in which the personal was political and the political was personal. This was not, however, something that Major was readily inclined to recognise – particularly in the midst of the notorious string of sexual and financial scandals that plagued nearly a dozen Conservative ministers and MPs during the 1990s. By trying to claim that the personal lives of erring ministers like David Mellor and Tim Yeo were "purely private matters", Major refused to acknowledge the extent to which years of stories by these very tabloids on ‘private matters’ like sexual morality had served to bolster his party’s standing with the electorate. To Major, "Back to Basics" may well have been a cynical communications exercise – yet for the press, it was deeply intertwined with one of the defining news agendas of the era.

As is well known, the disintegration of the Conservative-Murdoch alliance under Major was swift and brutal. The devastating effectiveness with which the tabloid press dismantled Major’s hopes of re-election in 1997 revealed the unassailable position of strength to which it had ascended during the Thatcher years. Though sleaze was not the only issue at stake in Major’s twilight hours, it was the means by which the tabloids were able to control the news agenda and drown out any attempt by the government to regain the political initiative. The Sun’s headline on Black Wednesday, "Now we’ve ALL been screwed by the Cabinet", is a brilliant example of the way in which it kept sleaze at the forefront of political consciousness.

Major’s landslide defeat in 1997 was a cautionary tale for future leaders on the perils of estranging the Murdoch empire. As the efforts of Blair, Brown and Cameron to curry favour with News International have shown, Major was the last Prime Minister to fail to appreciate the power of Murdoch and the tabloid press. After his example, no leader would make that mistake again.