# Mark Costello Mark Costello is a Republican member of the Iowa Senate for district 8. - Party: Republican - Seat: Iowa Senate, district 8 - Serving since: 2023-01-03 - Current term: IA 2025–26 session - Open States ID: ocd-person/37b1879c-5435-4c28-bb62-fa71fbabbbdb Source: https://americaspoliticalpulse.com/p/37b1879c-5435-4c28-bb62-fa71fbabbbdb (America’s Political Pulse, Polarization Research Lab), data through 2026-10-27. Data under CC BY 4.0. Cite as: Westwood, Sean J., and Yphtach Lelkes. 2024. America's Political Pulse [data set]. ## Headline Costello sits at +0.68 on the CSIP scale, more conservative than 89% of State Senate Republicans. ## Ideology (CSIP) CSIP score +0.68 (standard error 0.04), from 109 donors and 936 roll calls. Negative is left of 0, positive right of it, on one scale for every official. 89% of State Senate Republicans score lower. ## Votes (IA 2025–26 session) 589 roll calls. Attendance 99.6% (Iowa Senate 93.9%). Party unity 98.9% (95.7%). 8 votes against the party majority. Key votes: - 2026-10-02 · voted yea · Shall the bill pass? · HF 2801 A bill for an act modifying the major economic growth attraction program, and including effective date provisions. · pass · https://openstates.org/ia/bills/2025-2026/HF2801/ - 2026-05-03 · voted yea · Shall the bill pass? · SF 2472 A bill for an act relating to state and local government taxes, fees, financial authority, and budgets, by modifying property assessment provisions,… · pass · https://openstates.org/ia/bills/2025-2026/SF2472/ - 2026-05-03 · voted yea · Shall the bill pass? · HF 2788 A bill for an act relating to abortions including definitions, informed consent, dispensing of abortion-inducing drugs, and other abortion-related… · pass · https://openstates.org/ia/bills/2025-2026/HF2788/ - 2026-05-02 · voted yea · Shall the bill pass? · HF 2765 A bill for an act providing for the regulation of mining, making penalties applicable, and including effective date provisions. · pass · https://openstates.org/ia/bills/2025-2026/HF2765/ - 2026-05-02 · voted yea · Shall the bill pass? · HF 1036 A bill for an act relating to human trafficking, including screening children, civil statutes of limitations, an annual stakeholder meeting and… · pass · https://openstates.org/ia/bills/2025-2026/HF1036/ - 2026-05-02 · voted nay · Shall amendment S-5251 be adopted? · HF 1036 A bill for an act relating to human trafficking, including screening children, civil statutes of limitations, an annual stakeholder meeting and… · fail · https://openstates.org/ia/bills/2025-2026/HF1036/ - 2026-05-02 · voted yea · Shall the bill pass? · HF 2787 A bill for an act prohibiting warrant resolution clinics, including enforcement mechanisms, providing penalties, and including effective date… · pass · https://openstates.org/ia/bills/2025-2026/HF2787/ - 2026-05-02 · voted yea · Shall the bill pass? · HF 2781 A bill for an act relating to allocations of moneys from the juvenile detention home fund. · pass · https://openstates.org/ia/bills/2025-2026/HF2781/ - 2026-05-02 · voted yea · Shall the bill pass? · HF 2542 A bill for an act relating to habitual offenders, and providing penalties. · pass · https://openstates.org/ia/bills/2025-2026/HF2542/ - 2026-05-02 · voted yea · Shall the bill pass? · HF 2493 A bill for an act relating to the statewide preschool program by modifying provisions relating to eligibility, funding, and compulsory attendance and… · pass · https://openstates.org/ia/bills/2025-2026/HF2493/ ## Legislation (IA 2025–26 session) Sponsored 10 bills: 10 reached committee, 2 passed one chamber, 0 passed both, 0 became law. Cosponsored 0. 20.0% of sponsored bills got out of committee (Iowa Senate 10.8%; rank 9 of 48). Recent sponsored bills: - SR 111: A resolution recognizing the 150th anniversary of the establishment of the University of Northern Iowa. (passed one chamber, 2026-03-25) https://openstates.org/ia/bills/2025-2026/SR111/ - SJR 2008: A joint resolution supporting devolution of power from the United States department of education to the states. (in committee, 2026-02-19) https://openstates.org/ia/bills/2025-2026/SJR2008/ - SR 104: A resolution recognizing and honoring the Young Men’s Christian Association (in committee, 2026-01-21) https://openstates.org/ia/bills/2025-2026/SR104/ - SR 101: A resolution honoring Staff Sergeant William Nathaniel Howard, Staff Sergeant Edgar Brian Torres-Tovar, and their families. (passed one chamber, 2026-01-15) https://openstates.org/ia/bills/2025-2026/SR101/ - SF 500: A bill for an act relating to establishing the school security personnel grant program within the department of homeland security and emergency management and… (in committee, 2025-03-06) https://openstates.org/ia/bills/2025-2026/SF500/ - SF 375: A bill for an act relating to the maximum power output for low-speed electric bicycles and pedestrian conveyances powered by an electric motor. (in committee, 2025-03-04) https://openstates.org/ia/bills/2025-2026/SF375/ - SF 367: A bill for an act designating kratom as a schedule I controlled substance, and making penalties applicable. (in committee, 2025-02-20) https://openstates.org/ia/bills/2025-2026/SF367/ - SJR 6: A joint resolution proposing an amendment to the Constitution of the State of Iowa by repealing the natural resources and outdoor recreation trust fund, and… (in committee, 2025-02-19) https://openstates.org/ia/bills/2025-2026/SJR6/ - SF 320: A bill for an act creating a capital murder offense by establishing the penalty of death for murder in the first degree of a peace officer on duty, and… (in committee, 2025-03-03) https://openstates.org/ia/bills/2025-2026/SF320/ - SF 331: A bill for an act relating to the purchasing of a youth deer hunting license and tag. (in committee, 2025-02-25) https://openstates.org/ia/bills/2025-2026/SF331/ ## Campaign money (2026 cycle) Itemized receipts $33.6K (State Senate Republicans median $46.2K). 100% of itemized individual money came from in state. Aggregates only; no individual donors. ## Links - Official site: https://www.legis.iowa.gov/legislators/legislator/legislatorAllYears?personID=10749 - Facebook: https://www.facebook.com/CostelloForSenate/ - LinkedIn: https://www.linkedin.com/in/mark-costello-182a879b Full profile, with every chart and the methods: https://americaspoliticalpulse.com/p/37b1879c-5435-4c28-bb62-fa71fbabbbdb