Drew Ensign is a partner at Holtzman Vogel, focusing his practice in Appellate, Commercial Litigation, Constitutional Law, Election Law and Environmental Litigation.

Prior to joining the firm, Drew served in the Arizona Attorney General’s Office, where he was concurrently a Deputy Solicitor General and Section Chief of the Civil Appeals and Federalism Section. In that role, he led several challenges to federal governmental actions, including a 24-state challenge to CDC’s termination of the Title 42 System in Louisiana v. CDC, a 14-state challenge to the CMS Vaccine Mandate in Biden v. Missouri, and Arizona’s challenge to the 2021 Tax Mandate in Arizona v. Yellen. He also oversaw all civil appellate matters for the State of Arizona, including supervision of more than 400 briefs annually.

Drew also led or co-led merits briefing in the U.S. Supreme Court in Brnovich v. DNC, Arizona v. San Francisco (12 states) and Arizona v. Mayorkas (19 states). He also led multi-state amicus briefs in United States v. Texas (18 states), NY State Rifle & Pistol Ass’n, Inc. v. Corlett (26 states), Vega v. Tekoh (22 states), Americans for Prosperity Found. v. Bonta (22 states), and Lomax v. Ortiz-Marquez (32 states). Drew was set to argue Arizona v. Mayorkas until the federal government mooted the case.

In appellate law, Drew has authored briefs in the U.S. Supreme Court, ten of the thirteen federal circuit courts, and each of Arizona’s appellate courts. He has argued five times in the Arizona Supreme Court, and has also argued appeals in the Ninth, Tenth, D.C., and Federal Circuits, as well as both divisions of the Arizona Court of Appeals.

Drew also has extensive experience in election law. In addition to Brnovich, he led Arizona’s successful defense of its election statutes and procedures in Arizona Democratic Party v. Hobbs, (challenge to non-signature curing), Miracle v. Hobbs (challenge to statute regulating initiative signature gathering), Arizonans for Second Chances v. Hobbs (challenge to Arizona’s wet signature requirement for initiatives during COVID-19 pandemic), Arizonans for Fair Elections v. Hobbs (same), and Mi Familia Vota v. Hobbs (challenge to registration deadline to vote in 2020 election).

In the environmental law and litigation space, Drew prepared drafts of the successful petitions for certiorari and merits briefs in two Supreme Court environmental cases: Entergy Corp. v. Riverkeeper, Inc. (2009), involving the Clean Water Act (CWA), and Monsanto Co. v. Geertson Seed Farms (2010) (6-3 victory), involving the National Environmental Policy Act (NEPA) (7-1 victory). He has also litigated cases involving many other environmental statutes, including the Clean Air Act (CAA), the Endangered Species Act (ESA), the Energy Policy and Conservation Act (EPCA), the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the Federal Food, Drug, and Cosmetic Act (FFDCA), the Plant Protection Act (PPA), and the Safe Drinking Water Act (SDWA). 

Prior to the Arizona Attorney General’s Office, Drew was at an AmLaw 100 firm and served as a law clerk to the Honorable J. Clifford Wallace on the U.S. Court of Appeals from the Ninth Circuit.

 

Clerkship/Government Experience
  • Arizona Attorney General’s Office, Deputy Solicitor General and Section Chief of the Civil Appeals and Federalism Section (2019-2022); Senior Litigation Counsel (2017-19)
  • Law clerk to the Honorable J. Clifford Wallace on the U.S. Court of Appeals Ninth Circuit (2005-2006)

Representative Actions Challenging Governmental Actions

  • 24-state challenge to CDC’s termination of the Title 42 System in Louisiana v. CDC, 603 F. Supp. 3d 406 (W.D. La. 2022)
  • 14-state challenge to the CMS Vaccine Mandate in Biden v. Missouri, 142 S. Ct. 647 (2022)
  • Arizona’s challenge to the 2021 Tax Mandate in Arizona v. Yellen, 34 F.4th 841 (9th Cir. 2022)

U.S. Supreme Court Merit Briefs

  • Brnovich v. DNC, 141 S. Ct. 2321 (2021)
  • Arizona v. San Francisco, 142 S. Ct. 1926 (2022)
  • Arizona v. Mayorkas, 143. S. Ct. 1312 (2023)
  • Monsanto Co. v. Geertson Seed Farms, 561 U.S. 139 (2010)
  • Entergy Corp. v. Riverkeeper, Inc., 556 U.S. 208 (2009)

Multi-State Amicus Briefs

  • United States v. Texas, 143 S. Ct. 1964 (2023) (18 states)
  • NY State Rifle & Pistol Ass’n, Inc. v. Corlett, 142 S. Ct. 2111 (2022) (26 states)
  • Vega v. Tekoh, 142 S. Ct. 2095 (2022) (22 states)
  • Americans for Prosperity Found. v. Bonta, 141 S. Ct. 2373 (2021) (22 states)
  • Lomax v. Ortiz-Marquez, 140 S. Ct. 172 (2020) (32 states)

Election Law Matters

  • Brnovich v. DNC, 141 S. Ct. 2321 (2021)
  • Arizona Democratic Party v. Hobbs, 18 F.4th 1179 (9th Cir. 2021) (challenge to non-signature curing)
  • Miracle v. Hobbs, 808 Fed. App’x 470 (9th Cir. 2020) (challenge to statute regulating initiative signature gathering)
  • Arizonans for Second Chances v. Hobbs, 249 Ariz. 396 (2020) (challenge to Arizona’s wet signature requirement for initiatives during COVID-19 pandemic)
  • Arizonans for Fair Elections v. Hobbs, 454 F. Supp. 3d 910 (D. Ariz. 2020) 
  • Mi Familia Vota v. Hobbs, 977 F.3d 948 (9th Cir. 2020) (challenge to registration deadline to vote in 2020 election)

Environmental Litigation Cases

  • Monsanto Co. v. Geertson Seed Farms, 561 U.S. 139 (2010) (NEPA)  
  • Entergy Corp. v. Riverkeeper, Inc., 556 U.S. 208 (2009) (CWA)
  • Louisiana v. DOE, No. 22-60146 (5th Cir. 2022) (EPCA)
  • Arizona v. EPA, 77 F.4th 1126 (D.C. Cir. 2023) (SDWA)
  • Center for Food Safety v. Vilsack, 718 F.3d 829 (9th Cir. 2013) (ESA, NEPA, and PPA)
  • Center for Food Safety v. Vilsack, 636 F.3d 1166 (9th Cir. 2011) (NEPA)
  • National Corn Growers Ass’n v. EPA, 613 F.3d 266 (D.C. Cir. 2010) (FFDCA)

 

Related Practice Areas
  • New York University School of Law, J.D., magna cum laude
    • NYU Law Review, Notes Editor
    • Order of the Coif
    • Butler Scholar
  • Duke University, B.S., magna cum laude with highest honors, Economics and Public Policy Studies
    • Duke Student Government (Executive Vice President and Vice President for Academic Affairs)
    • Best Honors Thesis (Public Policy Studies Department)
    • Paul Edwin Harner Award (“Four Year” Student Leadership Award)
  • Arizona Bar
  • California Bar
  • District of Columbia Bar
  • U.S. Supreme Court
  • U.S. Court of Appeals for the 1st, 2nd, 5th, 6th, 7th, 8th, 9th, 10th, 11th, D.C., and Federal Circuits
  • U.S. District Courts (Arizona, Central District of California, Northern District of California, District of Columbia, Southern District of Indiana, Northern District of Texas)
Drew Ensign Photo