427 out of 435 House seats in the 2020 election have been called (by the Associated Press) but it is already clear that all U.S. Representatives among the longest-serving members of the House have won reelection. Some are disappearing from the list nevertheless since they didn't run in the first place or sadly passed.
The longest serving U.S. representative, Don Young (R-AK), has been working in the Capitol for 48 years and will return in the 2021 term after beating his Democratic challenger with 54.5 percent of the vote. While Young started his first term in the beginning of 1973, three more Representatives had their debuts in 1981 and are still going strong after 40 years. Chris Smith (R-NJ), Steny Hoyer (D-MD) and Hal Rogers (R-KY) all brought in decisive wins at 60 percent, 69 percent and a whopping 84 percent of the vote, respectively.
Rep. John Lewis - formerly in a joint fifth place on the list - died in office earlier in the year at age 80. The civil rights leader from Georgia was serving his 34th year in Congress. Fellow Democrat Peter Visclosky (D-IN) was fourth on the list of the longest-serving Representatives, having started his first term two years before Lewis, in 1985. Visclosky did not give a reason why he wasn't seeking reelection in 2020 after 36 years, but The New York Times named him among a group of moderates on both sides of the isle that are quitting Congress in 2021.
Two long-time Reps had already left Congress after the 2018 midterms at their own discretion. Tea party member Joe Barton (R-TX) had served 34 years since 1985 and weathered the odd scandal before calling it a day at age 69. Rep. Sandy Levin (D-MI) proved a special incumbent advantage. He didn't seek reelection after 36 years in Congress, but his son Andy ran and promptly won his father's seat. He will return for a second term in January.