[4] On 26 April 2012, Galletti was elected leader of the Union of Centre in the Chamber of Deputies, replacing his political mentor Pier Ferdinando Casini.

[6] His nomination was harshly criticized by many green associations due to his support to nuclear power; Monica Frassoni, a former MEP, accused Galletti of being only known as the "tax advisor of Pier Ferdinando Casini".

[7] During the Italian rotating presidency of the EU Council in 2014, he led to the modification of the European legislation on GMOs, allowing each state to have decision-making autonomy on the cultivation of genetically modified organisms on its territory.

[12] In the run-up of the constitutional referendum the Union of the Centre chose to campaign for "No", while Galletti, Casini and other centrist deputies were among the keenest supporters of "Yes".

[13] Galletti decided not to run in the 2018 general election, which then saw a large defeat of the centre-left coalition, to which his new party as part of the Popular Civic List belonged, (although Casini was reelected) and a plurality for the centre-right led by the populist League of Matteo Salvini, but also a strong showing for the anti-establishment Five Star Movement.