Arlington County Board member Jay Fisette (D) in 2015. (Jahi Chikwendiu/The Washington Post)

Longtime Arlington County Board member Jay Fisette will not run for reelection this fall, potentially setting up a Democratic battle for what has been a reliably progressive seat on the five-member panel.

Fisette (D), who will be 61 on Saturday, said he figures he has one more career shift in him after nearly 20 years on the board, including five terms as chair.

He said he has no plans to run for higher office but wants to work on “embracing and advancing a set of progressive values that are so important to me, values we have championed here in Arlington that are threatened by the [Trump] administration.”

Well known throughout the region for his work on environmental and transportation issues, Fisette is a member of the Northern Virginia Transportation Authority and in 2007 won the Metropolitan Washington Council of Government’s highest honor for public service.

He said Wednesday that he is most proud of his efforts to “advance Arlington’s long-term sustainability,” which he said encompasses everything from saving open space in the geographically small county to increasing affordable housing for lower-income families. He led a 2010 initiative for a community energy plan intended to reduce energy costs and lower the county’s carbon footprint.

A major supporter of “new urbanism” principles that promote dense, walkable neighborhoods that combine housing, retail and job centers, Fisette has also paid attention to community sentiment, such as complaints about the location of a new fire station and unwanted noise from taverns below high-rise condos.

“I attempted to treat people with respect and be fair,” he said.

Fisette, who was the first openly gay elected official in Virginia, said Arlington “embraced me as a gay man long before such an endorsement could be presumed, long before it became the norm.” He said he has worked to make sure the community has remained inclusive and welcoming to all people.

Fisette’s decision to cancel the long-planned Columbia Pike streetcar in 2014 enraged those who for years had supported the transit and development project. But Fisette maintained that community opposition to the costly project, along with the election of anti-streetcar candidate John Vihstadt (I) to the County Board, meant the effort was no longer viable.

He is the longest-serving member of the current board and the second-longest-serving in county history, after 24-year board member Ellen Bozman (D), who stepped down in 1997. The other four current board members — all Democrats except Vihstadt — were elected in 2012, 2014 and 2015.

The Arlington County Democratic Committee decided earlier this month to hold a May caucus rather than a primary to choose nominees for the November general election. No one has announced plans to run for Fisette’s seat, but three Democrats who have unsuccessfully sought County Board seats in the past five years are expected to be interested.

The deadline for announcing will be 7 p.m. March 30, said county Democratic Party chair Kip Malinosky.

Fisette plans to serve out his term this year. Before his 1998 election to the board, he was director of the Whitman-Walker Clinic of Northern Virginia, a staff consultant to the Senate’s labor committee and an auditor with what was then called the General Accounting Office.

A Pittsburgh native, he graduated from Bucknell University and received a master’s degree in public and international affairs from the University of Pittsburgh.

He has lived in Arlington since 1983, and he and his husband, Bob Rosen, have been residents of the Ashton Heights neighborhood since 1987.