Her political interests include community support, women's issues, reconciliation, multiculturalism, the natural environment and social justice. During her time as Labor member she claimed a number of government achievements in information technology, including the opening of an online access centre in Clarendon Vale and the $4 million "Laptops for Teachers" program. She also spoke out against the Howard federal government's sale of Telstra. Other programs she was involved in included: diabetes camps for teenagers, 2004 Indian Ocean earthquake aid efforts and Landcare Australia funding deals. In 2005, Thorp quoted, in tears, lyrics from John Lennon's song "Imagine", when the government introduced new anti-terrorism laws.
Thorp faced election in the division of Rumney on 7 May 2005, and won with an outright majority of 50.96%, so there was no need to distribute preferences. She became Minister for Human Services on 17 September 2008.
As a Legislative Councillor, she was not up for re-election at the 2010 Tasmanian State Election. However, the ensuing portfolio reshuffle on 21 April 2010, saw her become the new Minister for Education and Skills, Minister for Children, and Minister for Police and Emergency Management.
She was defeated by Tony Mulder at the elections held on 7 May 2011.