In this paper, John Ahlquist argues that in the US, the extension of collective bargaining rights and formation of public sector labour unions requires the prior existence of these rights among signicant sections of the private sector economy. He says the secular decline in private sector unionisation will undermine the political bases of support for public sector unions. Ahlquist demonstrates that public sector unionism emerged where private sector unions were initially strong. Declining private sector unionism has led to a marked decrease in support for public sector unions. The diminution of their allies in the private sector and the prospect of extended periods of austerity at the state and local level have put public sector unions in a precarious position that Republican governors and legislatures are taking full advantage of, leaving the prospects for renewal in the labour movement dim.