2006 To challenge House District 41 incumbent Republican Representative Carol Mumford, Marcello was unopposed for the September 12, 2006 Democratic Primary, but lost the November 7, 2006 General election to Representative Mumford.
2008 When Representative Mumford retired and left the seat open, Marcello was unopposed for the September 9, 2008 Democratic Primary, winning with 217 votes[5] and won the November 4, 2008 General election with 4,285 votes (54.2%) against Republican nominee Christopher Caluori.[6]
2010 Marcello was unopposed for the September 23, 2010 Democratic Primary, winning with 614 votes[7] and won the November 2, 2010 General election with 3,450 votes (52.9%) against Republican nominee Marco Lucci.[8]
2012 Marcello was unopposed for the September 11, 2012 Democratic Primary, winning with 331 votes[9] and won the three-way November 6, 2012 General election with 4,171 votes (55.4%) against returning 2010 Republican challenger Marco Lucci and Independent candidate Lee Grossguth.[10]
2014 Marcello was unopposed in the Democratic primary on September 9, 2014.[11] He then won the General election on November 4, 2014 with 2,736 votes against Republican Lillian Delmonico and Independent candidate Robert Quattrocchi.[12]
2016 Marcello was unopposed in the Rhode Island House of Representatives District 41 Democratic primary on September 13, 2016.[13] He then lost the General election on November 8, 2016 to Republican candidate Robert Quattrocchi (who previously faced Marcello as an independent) with 3,871 votes to Quattrocchi's 4,058.[14]