He wasn’t a Congressman for 26 years. He served 5 terms — that is 10 years.
Sloppy writers.
"Prior to being elected five times to serve the citizens of Oakland and Wayne Counties in the United States House of Representatives, Rep. McCotter also represented the people in the Michigan State Senate and the Wayne County Commission. While on the Commission, he helped change the county charter to require that no new taxes can be enacted without the approval of two-thirds of the Commissioners and 60% of the voters."
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http://mccotter.house.gov/about-me/full-biography