Joni Kay Ernst (née Culver; born July 1, 1970) is an American politician and former military officer serving as the junior United States senator from Iowa since 2015. A member of the Republican Party, she previously served in the Iowa State Senate from 2011 to 2014 and as auditor of Montgomery County from 2004 to 2011. As Chair of the Senate Republican Policy Committee since 2023, Ernst is the fourth-ranking Republican in the Senate. After graduating from Iowa State University, Ernst joined the United States Army Reserve. She served in the Iowa Army National Guard from 1993 to 2015, retiring as a lieutenant colonel. During the Iraq War, she served as the commanding officer of the 1168th Transportation Company in Kuwait and later commanded the 185th Combat Sustainment Support Battalion at Camp Dodge, the Iowa Army National Guard's largest battalion. Ernst also holds a Master of Public Administration from Columbus State University.In 2004, Ernst was elected Montgomery County Auditor. She was reelected in 2008. In 2011, Ernst was elected to the Iowa State Senate in a special election and reelected in 2012. She represented District 12, in southwestern Iowa. Ernst ran for the United States Senate in 2014 and won, succeeding longtime Democratic Senator Tom Harkin and becoming the first Republican to win that seat since 1978. Having been strongly critical of President Barack Obama, she has been characterized as a reliable ally of President Donald Trump, and was thought to be a possible running mate in his 2016 campaign. Ernst was elected vice chair of the Senate Republican Conference in November 2018. She was reelected in 2020, defeating Democratic nominee Theresa Greenfield by 6.6 points.Ernst opposes legalizing abortion, and has supported a fetal personhood amendment and introduced legislation to defund Planned Parenthood. She opposes the Affordable Care Act and has called for reforms to Medicare, Medicaid, and Social Security. During the Trump administration, she expressed concern about, although not opposition to, Trump's trade war with China and criticized some aspects of his foreign policy. Ernst voted for the Tax Cuts and Jobs Act. While supporting both Trump's nominees for EPA administrator, she expressed concern over their commitment to the Renewable Fuel Standard. She rejects the scientific consensus on climate change. Ernst has opposed a federal minimum wage and advocated for the elimination of federal departments such as the Internal Revenue Service, Department of Education and the Environmental Protection Agency.