This question appears to focus upon different strands of thinking within conservatism, and within the Conservative party. 'One Nation' conservatism is associated with the party's paternalist tradition, while populism is associated to a large extent with the leadership of Margaret Thatcher, though there are earlier antecedents.
One Nation conservatism draws on those aspects of traditional, paternalistic conservatism that emphasise an organic society, continuity, concern for the underdog, and the responsibility borne by privileged rulers. Its origin is often attributed to the period of Disraeli in the 1860s, with a significant revival after the Second World War associated with Churchill, Butler, Macmillan and Macleod, and a commitment to Keynesianism, the mixed economy, the welfare state, conciliation of trades unions, planning, and the end of empire.
The traditional conservative view of society is that it is an organic whole, involving ties of mutual dependence, which in turn implies social duties and responsibilities as well as individual rights. Disraeli's novel, ‘Sybil’, attacks the whole system of capitalist values associated with industrialisation, and is based in part on nostalgia for an essentially romantic, and even fictitious past – a society of mutual dependence, where privilege entailed obligations, and where social division and class conflict did not exist. Disraeli referred to the ‘two nations’ ‘between whom there is no intercourse and no sympathy’ and, like later Conservatives who adopted the ‘One Nation’ slogan, hoped that social divisions could be transcended. There is an obvious electoral consideration here too – ‘the palace is not safe when the cottage is not happy’. Such paternalism has not always necessarily implied state action. Indeed it was very much the last rather than the first resort in the 19th century. Disraeli felt the necessary help should be provided by the aristocracy and the church, and from voluntary activity. His targets in ‘Sybil’ were uncaring landowners who neglected their tenants and new exploitative capitalists. In Shrewsbury in 1843 he blamed current political evils on the acquisition and development of property that was divorced from duty. By 1872, Disraeli was describing the ‘elevation of the condition of the people’ as the third great object of the Tory party.
One Nation Conservatism was prominent between the 1930s and 1960s. Chamberlain’s interventionist policies to rationalise industry in the 1930s were followed by Macmillan's advocacy of an interventionist ‘Middle Way’ between laissez-faire capitalism and socialist state planning in the 1950s. The wartime Tory Reform Group had urged the acceptance of social reform, while the recommendations of the Beveridge Report, the forerunner of the modern welfare state, were declared to be ‘the very essence of Toryism’. Butler (1947) explained that ‘We are not frightened at the use of the State’, a view endorsed by Eden: ‘We are not the political children of the laissez-faire school. We opposed them decade after decade.’ This having been said, the Churchill, Eden, Macmillan and Home governments grudgingly accepted many of the policies enacted by the 1945-51 Labour government, and so were committed to a 'post-war consensus', with support for the welfare state, full employment, government intervention in the economy, nationalised industries and a corporatist style of policy-making. The Welfare State established by the wartime Coalition and 1945-51 Labour governments was maintained, and even enhanced. A policy of compromise and accommodation was applied to the unions. And, after the denationalisation of steel and road haulage, other industries remained in public ownership. The role of government continued to expand, as did public expenditure; indeed, Macmillan accepted the resignation of his entire Treasury team in 1958 rather than the spending cuts they demanded. The party remained commited to full employment, and through the use of orthodox Keynesian demand management policies. When such policies failed either to raise growth or to prevent recurring sterling crises Macmillan’s government went for more intervention rather than free market solutions in the shape of NEDC (long term economic planning) and the NIC (incomes policy).
Populism represents another strand in conservative thinking. For much of the time, it was particularly associated with imperialism, nationalism and even chauvinism. Disraeli’s assiduous promotion of imperialism and the national interest associated the Conservatives with patriotism, a highly successful electoral strategy, particularly with the newly enfranchised working classes. >From the 1880s to the 1960s liberals, radicals and socialists were constantly accused in party literature of being unpatriotic and undermining English and imperial interests. In 1900 the radicals were associated with ‘a Small England, a Shrunken England, a Degraded England, a Submissive England’; a 1910 pamphlet claimed ‘If you fight for radical socialism you fight for a divided nation, a divided Kingdom ..the Union sold! In 1924, the Labour Government was accused of putting ‘the foreigner first’ and preferring ‘the Bolsheviks’ to ‘our own people’. The party successfully exploited the patriotic theme, reinforcing its claims to stand above narrow class interests, but instead for the nation as a whole, or to cite the late Lord Hailsham, ‘Being Conservative is only another way of being British’.
Baldwin and Churchill were particularly astute in associating themselves and their party with British values and interests, but the more internationalist climate after the war, coupled with the decline in empire, made patriotic rhetoric seem outmoded. Macmillan and Heath pursued entry into the EEC, but Powell’s English nationalism, expressed in his opposition to black immigration, the EEC and concessions to the Catholics in Ulster, showed that chauvinism still had popular appeal, especially with the working class. The Falklands War was the most dramatic illustration of renewed Conservative nationalism, while the emphatic assertion of British interests has been a consistent theme in defence and foreign policy since 1979.
In the period since 1970, and particularly after Thatcher's first general election victory in 1979, populist values again came to the fore in many areas of policy, and not simply confined to assertions of patriotism. Heath and, more particularly, Thatcher led governments that challenged the post-war ‘consensus’ described earlier. They placed much greater emphasis upon cutting government spending and taxation, combating inflation, ‘sound money’, market economics and privatisation, as well as rejecting the role of unions and other pressure groups in policy-making and challenging the ‘dependency culture’ of the welfare state. Most of these radical policies certainly had a populist edge. Thatcher's overtly ideological approach to politics had many of its roots in populism, and was in sharp contrast to earlier pragmatism, elitism and cautious gradualism. Thatcher described herself as a ‘conviction politician’, who was averse to traditional compromise and consensus, and was a populist in her championing of ‘ordinary people’ against established interests – though, ironically, she was never particularly popular in the country.
Hall and Jacques (1983) and Gamble (1989) refer to ‘authoritarian populism’ to describe Thatcher's support for a combination of free markets and some traditional (and popular) conservative elements – patriotism, law and order, authority and strong government. In a very real sense Thatcherite populism can be interpreted as a product of one form of liberalism and a reaction against another. Neo-liberalism involved a reaction against Keynesianism and the welfare state; neo-conservatism involved a reaction against the pervasive progressive ‘liberal’ permissiveness of the 1960s (abolition of capital punishment, relaxation of censorship, divorce law reform, legalisation of abortion and homosexuality), with critics (generally on the Right) blaming the breakdown of marriage, family life and moral standards more generally on the permissive society.
Conservative tensions are essentially those between Thatcherites and modernisers (the successors to the One Nation tradition), and remain to this day. The former are very much in the Classical Liberalism tradition, with their emphasis upon the enterprise culture, reduced state involvement in the economy, lower personal and business taxes, attacks on the dependency culture, etc. There is also significant moral/social authoritarianism (support for the family, law and order, traditional values) and nationalism (seen in attitudes to the EU and to immigration and asylum seekers). Modernisers, and David Cameron should be included in their number, are much more in the tradition of One Nation conservatism, believing the party should be more inclusive and tolerant, and that the stress in policy should be on social responsibility and on 'mending a broken society'. They also have much in common with New Liberalism, given their support for (a reformed) Welfare State and their recognition that citizens have diverse lifestyles, and are entitled to equal opportunities.
I hope this is helpful.