After winning the 2002 Democratic primary, Paccione was elected as a Democrat to the Republican-controlled Colorado House of Representatives from House District 53, representing western Fort Collins. She defeated Republican Kirk Brush by roughly 700 votes, or about 4 percentage points, and was sworn in during January 2003 as a member of the minority party in a Republican-controlled legislature. Following her first election, Paccione was cited and fined twice by the state of Colorado for filing late campaign finance reports; roughly one-quarter of legislators elected in that cycle were similarly cited, but the fines were used against her in her later Congressional campaign.