The current electoral system, adopted in 2003 and modified in 2009 and 2015, requires party lists to pass a 3% threshold in order to obtain representation.

The Senate is responsible for taking cognizance of the charges brought by the House of Representatives against the President (or whoever replaces him/her) and members of the Comisión de Aforados even if they may have ceased to exercise their functions.

If the charge refers to offences committed in the exercise of his/her duties or unworthiness to serve for misconduct, the Senate may only discharge him/her from office and/or temporarily or permanently strip the accused of their political rights.

The accused, however, is brought to trial before the Supreme Court of Justice, if the evidence demonstrates the individual to be responsible for an infraction deserving of other penalties.

If the charge refers to common crimes, the Senate confines itself to declaring if there are grounds for further measures; in the affirmative, the accused is placed at the disposition of the Supreme Court.