You mustn't expect politicians in a democratic system to come up with ideologically pure, intellectually consistent policies. Their job is to put together a winning coalition of voters who have different and even conflicting interests, and if that requires compromises and even contradictions, so be it.

But they must appear to be consistent, and Marina Silva has mastered the art.

Until last month Silva was the vice presidential candidate of the smallest of Brazil's three main parties, a woman with a national reputation as an environmental activist but little prospect of high political office. President Dilma Rousseff was cruising serenely toward re-election in the first round of the elections on Oct. 5, despite the fact the Brazil's once-booming economy is in a recession. And then a small plane crashed.