Modern perspectives on American political development point to the ways in which Presidents can exploit critical periods in history marked by re-aligning elections, major shifts in elite perceptions of the prevailing order, and the eventual replacement of old regimes with new. As indicated in chapter 1, the election of 1932 represented just such a change as, some have argued, did the election of 1980. During such periods, Presidents have unusual freedom to repudiate the old order, to make major institutional innovations and to change the nature of the political agenda. As Stephen Skowronek, the leading exponent of this view, has convincingly argued, such Presidents may fail in the programmatic sense (Roosevelt's New Deal did not cure the Great Depression), but succeed in terms of providing administrations with great discretion over the terms and outcome of political debate. They can therefore, successfully engage in a ′Politics of Reconstruction′.

Within established political regimes Presidents have much less potential for producing policy changes independent of, societal and institutional constraints. Even so, for those incumbents fortunate enough to find themselves able to exploit what Skowronek calls the ′Politics of Articulation′, when the prevailing regime remains strong and the President and his party are keen to develop it in some direction or other, the potential for policy leadership remains high. Hence according to this thesis, Lyndon Johnson could, in the guise of the Great Society, extend the New Deal regime according to his own priorities and preferences.