Analysis - Brazil's Rousseff looks weak, but so do her election rivals

SAO PAULO (Reuters) - With Brazil's economy struggling, a scandal at its state-run oil company and nearly three-quarters of voters saying they want change from their government, President Dilma Rousseff looks vulnerable in her bid for re-election this October.

But for her to lose, somebody else has to win. And her two main rivals have big, potentially fatal flaws of their own.