2012 When Senate District 13 Democratic Senator Dede Feldman retired and left the seat open, O'Neill ran in the three-way June 5, 2012 Democratic Primary, winning with 2,620 votes (52.9%)[3] and was unopposed for the November 6, 2012 General election, winning with 15,516 votes.[4]
2002 When House District 15 incumbent Democratic Representative John Sanchezran for Governor of New Mexico and left the seat open, O'Neill ran in the three-way 2002 Democratic Primary but lost to Steven Archibeque,[5] who lost the November 5, 2002 General election to Republican nominee Teresa Zanetti.[6]
2004 To challenge Representative Zanetti, O'Neill was unopposed for the June 1, 2004 Democratic Primary, winning with 1,472 votes[7] but lost the November 2, 2004 General election to Representative Zanetti.[8]
2008 O'Neill and Representative Zanetti were both unopposed for their June 8, 2008 primaries,[9] setting up a rematch; O'Neill won the November 4, 2008 General election with 7,532 votes (52.1%) against Representative Zanetti.[10]
2010 O'Neill was unopposed for the June 1, 2010 Democratic Primary, winning with 1,522 votes[11] and the November 2, 2010 General election, winning with 5,545 votes (50.8%) against Republican nominee Justin Horwitz.[12]