Mr Kirchner is less popular than Mr Menem within his own Peronistmovement, and owed much of his success in the first round to the backing of Mr Duhalde's party machine in Buenos Aires province.
Indeed, it was Mr de la Rua's secret meetings with Mr Menem and the discredited old guard of the Peronist union movement, promoted by Mr Nosiglia, that first strained relations with his vice-president.
It is a symbol among the grassroots of the ruling Workers and Peronist Parties in Brazil and Argentina respectively, and the Movement of Popular Participation (MPP), one of the largest sectors in Uruguay's ruling party, the Broad Front.