In the midst of all the drama surrounding the 2022 congressional midterms, one race symbolizes the costs of political fratricide, born from the vanity of an ex-president’s perceived infallibility. Washington’s third congressional district was pretty safely in the red column heading into this cycle. Former President Donald Trump prevailed here by 4.2 percentage points in 2020. And its representative, Jaime Herrera Beutler (R), is a popular six-term congresswoman first elected on the eve of her 33rd birthday in 2010, replacing retiring Democratic Rep. Brian Baird, who had beaten his Republican opponents by 20+ points in each of the previous four...