In 1983 at age 23, Dantin became a municipal councillor in Chambéry under Rally for the Republic Mayor Pierre Dumas.

However, the fifth UMP MEP, Nora Berra, eventually did not take her seat due to her appointment to the government, which is why Dantin succeeded her.

At the time of his first election, Dantin was considered a protégé of Michel Barnier, the former agriculture minister, who served as European Commissioner for Internal Market and Services between 2010 and 2014.

From 2010 to 2011, he was also a member of the Special Committee on the policy challenges and budgetary resources for a sustainable European Union after 2013.

[3] In the 2020 election, Dantin ran for the Senate seat in Savoie held by Jean-Pierre Vial, who did not seek re-election.