Michael Vittori, was a school teacher and is now the current president of San Lorenzo. In order to wrest control of the country from Damien Moreau the Leverage team steals the election from Edwin Ribera, the corrupt incumbent president bankrolled by Moreau, and makes it seem as if Vittori wins.
Vittori was one of the handful of candidates who were so far behind in the polls as to be seen as harmless enough to leave unharmed (while more viable candidates were arrested on false charges). He was the only of these candidates who was not in some way a criminal, being merely dull and lacking in charisma.
Nate and Sophie, particularly Sophie, help transform Vittori into a viable candidate by teaching him to be confident and training him to give speeches and rally the people. In an effort to win over voters Sophie pretends to be his fiance in order to make him more likeable and help him deliver his message.
Thanks to various manipulations, Vittori dominates the presidential debate and goes into an election which has moved from Vittori being over 40 points behind Ribera, to: 'too close to call'. Receiving word that he has won (in the form of an unofficial mass email sent by team) Vittori is nearly kidnapped by the security forces but is rescued by Sophie.
After Sophie "dies" in front of him, taking a bullet for him from an apparent assassination attempt on live television, an obviously horrified Vittori rallies the crowd to take back the freedom that the assassins have sought to steal and heads to parliament, with the escaped General Flores and some sympathetic police officers. There he confront Ribera only to be shocked as Ribera (having been convinced by Nate) conceded the election to him, officially rendering him president.
Evidently still believing Rebecca (as Sophie was calling herself) is dead, he to resolves to honour her memory and lead the people of San Lorenzo with General Flores as his parliamentary representative and foreign affairs advisor.