In November 2006, Böhler announced that she wanted to run for senate as a member of the GreenLeft party. In 2006 she had advised the Socialist Party on their election program. She changed to GreenLeft because "self realization and the individual take a central place in their program and because the party pays close attention to the conservation and defense of the principles of the Rechtsstaat". In February 2007 she was placed on second place on the list, behind Tof Thissen. In order to run for office, Böhler had to obtain Dutch citizenship. She was elected to the Senate in 2007.