From the start her government's anti-corruption campaign was picked up in earnest by Brazilian media that went on to publish one embarrassing revelation after another -- including some about her senior aides that required them to resign or cling on to power and endure public humiliation.
The crackdown on corruption therefore was understandably slow. It took more than a million Brazilians, who went on a protest march in June, to demand an end to rampant corruption before the government could be seen to stir and move forward with the promised political cleanup.
Now analysts say the campaign, initially overtaken by tabloid media priorities, is at risk of emptying at least a third of the Legislature. That's about as many who'll need to quit if civilian and criminal courts go ahead with cases pending against the lawmakers.
That may not be a bad thing, analysts say, and infuse new blood into Congress. They admit, though, that the expected upheaval in legislative ranks may also give rise to opportunistic politicians who, with time, would likely pursue similar abuses.
Findings made public since a new transparency law came into effect indicate at least a third of the 594 Brazilian federal lawmakers have pending cases before criminal and administrative courts. Many of those cases relate to alleged cases of corruption.
What happens to those lawmakers before the parliamentary election next year would have an impact on the composition of a new Congress due to be chosen at the polls, MercoPress reported.
The "clean record" legislation followed a mass petition signed by more than a million Brazilians and calling for politics to be free of corrupt and irregular practices. A tall order, analysts say.
The law has raised the prospect that most if not all of those suspected or accused of financial or other irregularities will be barred from contesting in next year's election. Whether authorities would really go that far remains to be seen.
All political parties big and small have shown up politicians accused of some irregularity or other, and in many cases criminal acts that are likely to put many of them behind bars.
The new legislation aimed at cleaning up Brazilian politics and findings about incumbents have left the million marchers of June greatly vindicated, analysts said.
"They confirm a very negative evaluation of the current members of Congress," Claudio Weber Abramo, head of Transparency International's Brazil branch, said.
The congressional transparency "map" shows 190 of the 594 federal lawmakers, almost a third, are tainted by some irregularity and many are already facing criminal charges, while others remain under investigation.
At least 28 of the ruling Workers Party lawmakers are implicated, and other parties including those in the opposition are also faced with the disgrace of having elected members already convicted or facing conviction for corruption.
Of 14 active lawmakers with jail sentences, 13 had their potential jail terms changed to fines or community service.
Public opinion polls on performance and approval of the country's main institutions showed Brazil's Congress was always bottom of the list of institutions favored by the voters.
In a country with vigorous news management by competing sides, Brazilians will be going to the polls next year with detailed background on each of the candidates -- a first for Brazil.