Dubé was first elected to the Legislative Assembly of New Brunswick in the 1999 provincial election and was re-elected in 2003, 2006 and 2010. In her first term, she chaired the committee on health care and joined the cabinet immediately following her re-election first as Minister of Education and then, on February 14, 2006 as Minister of Family and Community Services. After her election to a third term she served in the opposition. She has been elected as Progressive Conservative Caucus chairperson in the Fall of 2007. In September 2010, she was re-elected four times in a row to the New Brunswick Legislature with one of the largest majorities.