 Poirier joined the New Brunswick cabinet following the 2003 election as minister responsible for the Office of Human Resources and retained that post until a cabinet shuffle in early 2006 when she became Minister of Local Government and Minister responsible for Aboriginal Affairs.She was re-elected in 2006 in which her party's government was defeated and went into opposition.On January 29, 2010, she was appointed to fill a vacant New Brunswick seat in the Canadian Senate by Prime Minister Stephen Harper.