He started his political career in the Italian People's Party (PPI), a Christian-democratic outfit, and was elected president of the Province of Florence in 2004, when he was just 29.

Leading Democrats who took part to the convention included Sergio Chiamparino, Arturo Parisi, Graziano Delrio, Ermete Realacci, Andrea Marcucci and Roberto Giachetti, but most of the speakers were people from the civil society, mainly entrepreneurs, artists and intellectuals.

[8][9] Among the ideas espoused by Renzi and his fellow Big-Bangers, many were genuinely liberal for a social-democratic party: labour market flexibility, abolition of professional bars, pension reform and cuts in public sector.

[14] On 25 November Renzi came second in the first round of the primary election with 35.5%, behind Pier Luigi Bersani (44.9%), but ahead of Nichi Vendola (15.6%), Laura Puppato (2.6%) and Bruno Tabacci (1.4%).

On 19 February 2017, during the PD National Assembly, Renzi resigned as Secretary of the party and announcing his candidacy for the next leadership election.

On 17 September, during an interview to Italian newspaper la Repubblica, Renzi announced his intention to leave the PD, and create new parliamentary groups led by himself.

Members of Reformist Base (BR), notably including its leaders Lorenzo Guerini and Luca Lotti, decided not to join the new movement, remaining within the PD.