He was appointed a member of the Arkansas Soil and Water Conservation Commission by Governor Bill Clinton in 1986, and continued in that role until 1994.

Berry was appointed to the House Appropriations Committee and served on the Military Construction and Veterans Affairs, Energy and Water, and Transportation subcommittees.

He was also chosen by Democratic Leadership to serve as Vice-Chair of the Steering and Policy Committees of the United States House of Representatives and as a member of the Leader's Senior Whip Team.

[citation needed] As one of the three House Democrats that sat on the House–Senate conference committee on the Medicare/prescription drug bill in 2003, he voiced many complaints about the administration's healthcare policies.

Berry visited Cuba with Blanche Lincoln to promote the removal of the trade embargo to create more markets for Arkansas agricultural products.

With tough opposition from more progressive candidates, Berry narrowly won the primary with 52% of the vote, thanks to aggressive campaigning in the rural areas north of the Mississippi Delta region.

However, he enjoyed easy re-election from 1996 on, carrying the district 67%–33% in 2004, and then running unopposed in 2008, while receiving support from donors and groups also opposing the Barack Obama presidential campaign that year.