Analysis - Brazil's Rousseff not a slam dunk for re-election

SAO PAULO (Reuters) - She's one of the world's most popular presidents with an approval rating that is the envy of her peers in richer countries struggling with debt crises and political deadlock - 79 percent and rising.

She presides over a country with record-low unemployment, a can-do optimism that invites comparisons to the post-war years in the United States, and a chance to showcase its progress when it hosts the football World Cup next year.