In the 2004 election, Sonney, a maintenance worker, challenged eight-term Representative Thomas J. Scrimenti to represent the 4th District in the Pennsylvania House of Representatives. He defeated the incumbent by 184 votes, running on a platform focused on healthcare and tax reform.[4] He was re-elected continuously until retiring in 2022.
From 2019 and until his retirement, Sonney chaired the House Education Committee.[2] In that role Sonney supported the reduction of cyber charter school costs placed on school districts.[5][6] He previously introduced on multiple occasions legislation that would have required parents to pay for their child's cyber charter school tuition.[7] In 2019, Sonney introduced a bill to require school districts to have a cyber schooling option.[8]