U.S. Rep. Diana DeGette on Tuesday named a new chief of staff for only the second time since the Denver Democrat took office nearly 25 years ago.

Joeana “Jo” Middleton, DeGette’s former deputy chief of staff and district director, takes over the top position from Lisa Cohen, who has run DeGette’s office since her first term in 1997.

“Jo’s passion for helping others and serving her community is second to none,” DeGette said in a statement.

“Her experience working directly with the people of Colorado’s 1st Congressional District will ensure that their voices and needs remain at the forefront of everything we do. I have the utmost confidence in Jo and couldn’t be more excited to see her take on this new role.”

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Prior to taking a job with DeGette in early 2019, Middleton worked for then-U.S. Sen. Claire McCaskill in the Missouri Democrat’s St. Louis office.

As chief of staff, Middleton will be responsible for overseeing DeGette’s offices in Washington, D.C., and Denver, as well as community outreach and the congresswoman’s legislative and committee activities.

Cohen plans to continue working for DeGette as a senior adviser through the end of the year, she told Colorado Politics.

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“I want to thank Lisa for her years of dedicated service to the constituents of the 1st Congressional District and her counsel and friendship to me,” DeGette said in a statement, adding that she wishes Cohen the “very best in all her future endeavors.”

DeGette, a former state lawmaker and the Colorado congressional delegation’s longest-serving member, is seeking a 14th term in next year’s election. Self-described “grassroots progressive” Neil Walia is challenging her in the Democratic primary.

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