In addition to his career at Agence France-Presse and Yahoo News, he is most known for chairing the White House Correspondents' Association and for his reboot of the White House Correspondents Dinner into its original format, which saw the elimination of the tradition of having a comedian as the featured speaker and an absence of A-list celebrities at the event.
[5] He began his career as an Agence France-Presse desk editor and worked as a Congressional and White House correspondent for 15 years, during which he covered the impeachment of Bill Clinton, Al Gore's presidential campaign, as well as the George W. Bush and Barack Obama administrations.
[11] He was elected president of the White House Correspondents' Association from 2018 to 2019, beating Major Garrett of CBS News, 121 to 90 votes.
[12][13] During the White House Correspondents Dinner of 2019, he announced an annual prize of $25,000 for the best piece of investigative political journalism focused on accountability in state government.
[14] In preparation of the dinner that year, Knox broke with tradition by making a departure from the lighthearted and star-studded atmosphere of previous years' dinners and giving it a more serious tone with the invitation of historian and biographer Ron Chernow, instead of a professional comedian, as the featured speaker.