In 2004, at the age of 21 years, Reimann was elected to the Council of States (Kantonsrat) for the Canton of St. Gallen.

[1] A fluent speaker of English, Reimann stood out early for fighting for a 2009 citizen's initiative with the aim to prohibit minarets in Switzerland.

He has stated that for him "Islam does not belong to Switzerland",[2] and he participated in the international counter-jihad conference in Zurich in 2010.

[1] In 2016, Reimann submitted a motion that would have withdrawn Switzerland's application for EU membership that was suspended in 1992.

[4] In March 2016, the National Council accepted Reimann's motion and voted to withdraw the application.