A lawyer by occupation, Blanc served as Mayor of Divonne-les-Bains (1991–2019) and represented the 3rd constituency of Ain in the National Assembly (2002–2016).

He represented the 3rd constituency of the Ain department in the National Assembly from 2002 until his resignation in 2016, triggered by his will to focus on his activities at the regional level.

In the Senate, where he sits on the Committee on Foreign Affairs, Defence and the Armed Forces,[7] he presides over an information group on Nagorno-Karabakh.

He has advocated a right-wing electoral alliance beyond The Republicans ahead of the 2022 legislative election to counter the left-wing New Ecological and Social People's Union (NUPES).

[10] Blanc expressed support for Zemmour's agenda-setting in the campaign leading up to the 2022 presidential election, but declined to join Reconquête, stating The Republicans should instead set a new course of action: "The right must tackle certain ideas head on: sovereignty, nationality, decline, immigration, identity, language, all themes that Zemmour makes his stock in trade".