Populist movements/parties generally claim to support 'common people' in face of economic & political elites (whose characterization as 'corrupt' often serves as explanation in lieu of systemic/structural analysis). So populism can be linked to many causes/ideologies.
Bonapartism has parallels with authoritarian-populism of Peronism which combined themes of obedience, order, and national unity with mass-based (that P referred to as 'shirtless ones') political support resentful of US imperialism and desirous of economic improvement.
Nationalism has been common component of populist regimes seeking to mobilize active public support through various means - elections, plebiscites, mass demonstrations. Results may be reactionary (Khomeini), socialist (Nyerere), marxist (Nkrumah).
Stuart Hall called Thatcherism 'authoritarian populism' suggesting that it reflected and responded to popular anxiety about relaxed moral standards and weakening social authority. New Right calls for economic 'initiative and enterprise' do stand alongside support for a strong state. During 1984-85 miners' strike, Thatcher referred to trade union militants as 'enemy within' against which nation must be protected.
In US, some call laissez-faire/anti-tax, traditional gender role/anti- abortion politics 'populist conservatism' because of belief that only way to change things is through mass political action. Paul Weyrich, Howard Phillips, et. al., refer to themselves (and almost exclusively white national movement) as 'radical.' Populist here means lower-middle income and working people dissatisfied with their circumstances who blame big institutions for their problems. Donald Warren identified such folks as 'middle american radicals' and essence of their ideology is that they believe that they pay for 'rich giving into demands of poor.'
There is also 'progressive populist' current (Jim Hightower/Harry Boyte types) in US emphasizing more equitable distribution of economic income & wealth and political power.
Perhaps 'middle-strata' populist Kevin Phillips is example of how today's US populists could go in *either* direction. Once celebrated Republican adviser ('southern strategy') and self-described 'conservative populist' declared his hopes for surge of 'progressive populism' in wake of contemporary upward economic redistribution.
And, of course, Ross Perot is indication that one can be a 'three billion dollar' populist... Michael Hoover