Before her own campaigns, Irvin was heavily involved in the Arkansas Republican Party. She was a youthful volunteer for Ronald W. Reagan in 1980, who won the state over DemocratJimmy Carter. In 1990, she worked in the Sheffield Nelson campaign for governor, but he was defeated by Bill Clinton. In 1994, Irvin again worked in the second Nelson campaign as the special events coordinator, but he was beaten by Democrat Jim Guy Tucker. Irvin won election in 2010 to the District 10 seat in the Arkansas Senate vacated by term-limited Democrat Paul Miller. She defeated Democrat Curren Everett, 14,865 to 10,204. In 2012, Irvin won election in District 18, revised after redistricting; the incumbent Republican Jason Rapert was moved to District 35. Irvin defeated Democrat William White and the IndependentPaul White, who had been her unsuccessful Republican primary opponent in 2010. Irvin polled 22,290 votes; William White, 15,442, and Paul White, 3,540. She is the Republican assistant President Pro Tempore for the First District. Irvin serves on the Arkansas Legislative Council and chairs the Senate Committee on City, County, and Local Affairs. She is vice chair of the Energy Committee and serves as well on Budget, Efficiency, and Public Health, Welfare and Labor. Irvin opposes abortion, having voted to ban the practice after twenty weeks of gestation or whenever fetal heartbeat is determined. She opposes allowing abortion to be covered in health-care plans. In 2011, she opposed a bill to ban cell phones in school zones. In 2013, Irvin joined the Senate majority to amend state income tax rates. She voted with the majority to reduce the amount of weekly unemployment compensation benefits and to require the recipients to be screened for illegal use of narcotics. She voted successfully to override Democratic Governor Mike Beebe's veto of a bill to require photo identification when one casts a ballot in Arkansas. She sponsored legislation to make the office of prosecuting attorney in Arkansas nonpartisan. She voted to allow handguns to be carried on church properties and to forbid the release of information on the holders of concealed carry permits. She voted to allow university staff to carry concealed weapons. She supported legislation to permit the sale of unpasteurizedwhole milk within the state. Irvin was re-nominated to her state Senate seat in the Republican primary election held on May 20, 2014. She polled 64 percent of the vote against her lone intraparty challenger, Phil Grace.