Morin was first elected as a representative to the French National Assembly on 16 June 2002, in the 3rd constituency of Eure, Normandy.

When Morin joined the government as minister of Defence in July 2007, Marc Vampa New Centre replaced him as representative.

Following the Battle of N'Djamena in 2008, Morin flew to Chad in a show of support for President Idriss Deby, who had just survived an assault on the capital by rebels seeking to topple him.

[2] In 2009, Morin rejected requests by U.S. President Barack Obama for reinforcements to Afghanistan, arguing the France had already deployed enough troops.

[3] He instead called on NATO partners to set specific timelines for achieving progress in Afghanistan in areas including security and governance.

[7] At the time of the announcement, he had the support of about 20 deputies, senators and European parliamentarians, and polls saw him winning only between 1-2 percent of the vote.

[10] In 2013, Jean-Louis Borloo of the Union of Democrats and Independents (UDI) included Morin in his shadow cabinet; in this capacity, he served as opposition counterpart to Minister of Economic Affairs and Finance Pierre Moscovici.

[14] Ahead of the 2022 presidential elections, Morin publicly declared his support for Valérie Pécresse as the Republicans’ candidate.