Mr Serra also lost (to Mr Gomes) the backing of much of the conservative LiberalFrontparty, one of the pillars of Mr Cardoso's coalition and powerful in Brazil's north-east.
The opposition, in this case led by the conservative LiberalFrontParty, demanded an unaffordable minimum wage purely to embarrass a left-wing president who had once promised to double it.
Its former coalition partner, the (conservative) Party of the LiberalFront, has changed its name to the Democrats as part of a stampede for the middle ground of Brazilian politics.