She was born Katherine Moore Porter on January 3, 1974 in Fort Dodge, Iowa, the daughter of Daniel Porter, a banker, and Liz Porter, a journalist, and she grew up on a farm near Fort Dodge. She earned a B.A. in American Studies from Yale in 1996 and a J.D. magna cum laude from Harvard Law in 2001, where she studied bankruptcy law under Elizabeth Warren, who was then a Harvard professor, and that mentorship went on to shape her whole career.
After Harvard she clerked for Judge Richard S. Arnold on the Eighth Circuit Court of Appeals from 2001 to 2002 and then worked at the litigation firm Lieff Cabraser from 2002 to 2004, and she taught at Iowa and UNLV before she joined UC Irvine School of Law in 2011 as a professor of consumer finance, bankruptcy, and commercial law, where in 2014 she published the textbook Modern Consumer Law.
In 2012, then-Attorney General Kamala Harris appointed her as California's independent monitor for the National Mortgage Settlement, where she oversaw compliance by Bank of America, JPMorgan, Wells Fargo, Citigroup, and Ally Financial under the $25 billion multistate settlement, and she served in that role until 2015. In November 2018 she won the CA-45 House seat against Republican Mimi Walters 52.1% to 47.9%, which flipped a Trump +5 district, and after the 2021 redistricting she won the new CA-47 in 2022 against Scott Baugh 51.7% to 48.3%.
Her House career was defined by the viral hearings she ran on the Financial Services Committee, and the one that went furthest was the April 10, 2019 hearing where she used her whiteboard to walk JPMorgan's Jamie Dimon through the $567-a-month shortfall a bank teller faces on JPMorgan's starting salary. She ran for Senate in 2024 and finished third with 15.3%, behind Schiff and Garvey, in the March 5 primary, and she announced her run for governor on March 11, 2025.
