It is not a matter of believing, but looking at the facts. Dilma is right when she says that since the beginning of the second term, congress has not done anything good.
And you should know that there is no evidence whatsoever that the president committed the crime that she is accused of. Nothing! not even a single shred of proof that she did anything against the law.
Presidents may not be impeached because other politicians do not like her. A president is choosen by the people to serve the country and the other politicians must respect the wishes of the people.