In 2010, Deffenbaugh was nominated in the Republican primary election in District 66 over Kevin R. Holmes, 1,426 to 719. He then defeated Democrat Dianna K. Faucher, 5,113 to 1,851 in the general election. The seat was vacated by the term-limited Republican Rick Green. In 2012, Deffenbaugh was nominated and elected without opposition in House District 79, which had been represented by the term-limited Democrat Mike Patterson. Deffenbaugh serves on these House committees: Education, Aging, Children and Youth, Legislative and Military Matters, Public Retirement and Social Security Programs, Legislative Joint Auditing. In 2013, Deffenbaugh voted to override the vetoes of Democratic GovernorMike Beebe to enact legislation to require photo identification for casting a ballot in Arkansas and to ban abortion after twenty weeks of gestation; he was a co-sponsor of both measures. Deffenbaugh also supported related legislation to ban abortion whenever fetal heartbeat is detected, to forbid the inclusion of abortion in the state insurance exchange, and to make the death of a fetus a felony in certain cases. Deffenbaugh co-sponsored a proposed spending cap in the state budget, but the measure failed to gain approval by two votes in the House. He also co-sponsored amending state income tax rates. Deffenbaugh co-sponsored separate legislation to allow officials of universities and religious institutions to carry concealed weapons. He voted to prohibit the governor from regulating firearms in an emergency. Deffenbaugh supported legislation to make the office of prosecuting attorney in Arkansas nonpartisan. He supported the bill, signed by Governor Beebe, to permit the sale of up to five hundred gallons per month of unpasteurizedwhole milk directly from the farm to consumers. He voted for a failed proposal to prohibit the closure of schools based on declining enrollments over a two-year period. He voted for the tiered system of lottery scholarships. In 2011, Deffenbaugh in District 66 supported dress codes for public schools. He backed curriculum standards for Bible instruction in public schools. He was a co-sponsor of both the Capital Gains Reduction Act and the tax reduction on manufacturers' utilities. He voted to prohibit the administration of driver's license tests in languages other than English. He voted against prohibiting cell phone use in school zones. Deffenbaugh voted against the congressional redistricting bill.
