In 1994, Hottinger made his first run for the Ohio House of Representatives. He was only 25 years old, but had already served on the Newark City Council for three years. He went on to defeat his challenger to succeed Marc Guthrie. He would win re-election in 1996. When Senator Nancy Dix resigned from the Senate in 1998, creating a vacancy in the 31st Senate District, Senate Republicans chose Hottinger to replace her. With the seat up for re-election in 1998, Hottinger faced former Senator Eugene Branstool, who had been defeated by Dix a few years prior. However, he went on to defeat Branstool with 58.85% of the vote. He ran unopposed for re-election in 2002. Later on in his Senate tenure, Hottinger served as assistant majority whip, as well as chairman of the Senate Insurance, Commerce and Labor Committee. He has been an outspoken critic of Medicaid expansion in Ohio. In 2005, Hottinger announced that he would seek his former House seat. Soon after, Hottinger was also mentioned as a potential running mate to gubernatorial candidate Ken Blackwell, who chose Rep. Tom Raga instead, however. Unopposed in the primary, he faced Democrat Thomas Holliday in the general election, and won with 61.83% of the vote. In his first term back into the House, Speaker of the HouseJon Husted appointed Hottinger as chairman of the House Finance Committee. Hottinger was reelected in 2008 against Democrat Howard Hill with 62% of the vote. In 2010, he won a third term in the House with 69.31% of the vote against Democrat Nathan McMann. He won a final House term in 2012 with 61% over Democrat Brady Jones.
Hottinger was term-limited in 2014, as was his predecessor in the 31st district of the Ohio Senate, Tim Schaffer. As a result, Hottinger announced he would run again for his former Senate seat. While his former district was also the 31st, the new 31st is entirely different following redistricting. Prior to 2012, the 31st included Fairfield, Licking, Perry, Hocking and parts of Pickaway counties. After, it includes Licking, Perry, Coshocton, Tuscarawas and parts of Holmes counties. As a result, the majority of the district Hottinger ran in for the 2014 election was different. Despite all of this, Hottinger won election to the Senate 65% to 35%. For the 131st Ohio General Assembly, Hottinger has been named as chairman of the Senate Insurance Committee.
On April 23, 2016, Laura Bischoff of The Dayton Daily News reported that Hottinger posted a racist joke on Instagram, which he later retracted. The joke, disparaging Asian Americans, was condemned by both Ohio Democratic Party Chairman David Pepper and Kathy Chen, executive director of Asian AmericanCommunity Services. Initially, Hottinger told an interviewer that there was nothing problematic about the joke, but he later recanted, stating, "It was inappropriate of me to put it up so I took it down and apologized."
