Romano Prodi

Prodi is the cautionary and admirable case at once. His Olive Tree coalition of 1996 squeezed Italy's deficit hard enough to qualify for the euro at launch, the result it had promised. Both his governments then fell because of tiny partners: Communist Refoundation brought down the first in 1998, and the second, holding the Senate by a handful of votes, collapsed in 2008 when a small centrist party walked out. He shows what a broad coalition can deliver, and how much power it gives to its smallest members.