Katz ran for the 4th district of the
Delaware Senate in 2008. At the time, Republicans had a voter registration advantage in the district. Katz campaigned on a platform of improving public schools and increasing access to healthcare. Katz won the Democratic nomination over nonprofit executive Dee Durham with 63.0% of the vote before edging out
Republican State Committee of Delaware member John Clatworthy in the general election by just 1.3%. While in office, Katz supported the movement to preserve the historic Murphy House; however, the house was demolished in 2012. Katz also introduced several bills aimed at increasing transparency requirements for lobbyists, though none of them passed committee. In 2011, Katz accused Democratic state representative
Bryon Short of plagiarizing a bill he wrote to establish an accreditation process for
abortion clinics. Katz also refused to list Short as a cosponsor on his bill due to what he perceived as Short's "poor treatment of the medical community during his private and public deliberations" on an earlier bill. Short acknowledged his bill was very similar to Katz's bill, but argued that both bills were based on language written by the Delaware Department of Health and Social Services and the Medical Society of Delaware months earlier. Short also believed that Katz's bill contained too many protections for doctors, saying "each piece of legislation Sen. Katz introduced has skewed in favor of his profession." Katz asked House Majority Leader
Pete Schwartzkopf to open an ethics investigation into Short, but Schwartzkopf refused, pointing out that only members of the House could make such a request. Schwartzkopf also commented that Katz "doesn’t think anyone should propose legislation involving doctors except for him." However, in 2012, Katz and Short collaborated on a bill to strengthen restrictions on
door-to-door salesmen that successfully passed the legislature. Katz ran for re-election in 2012 and was unopposed in the Democratic primary. In the general election, he faced Republican
Gregory Lavelle, the Minority Leader of the
Delaware House of Representatives. Lavelle had chosen to run for state senate after he and 4 other Republican state representatives were placed in the same district as a result of the
2010 redistricting cycle. Lavelle defeated Katz by a margin of 3.3%. Katz accepted the
Republican State Committee of Delaware's
nomination for the U.S. Senate at its April 25, 2026 convention in
Dover. ==Personal life==