CHICAGO (CBS) — Longtime northwest Indiana Congressman Pete Visclosky announced Wednesday he would not seek re-election in 2020, after 35 years in office.

Visclosky’s announcement comes on the 35th anniversary of his first election to the U.S. House of Representatives in 1984. He touted his longstanding support for the steel industry in northwest Indiana, which has several steel mills in the region.

“While some successes have been achieved, we still suffer from declining population – including the loss of over 15,000 school children since 2010.  And far too many people lack fulfilling employment, economic opportunity and the hope for a better future.  Much work remains to be done,” he said in a statement.

A Democrat from Gary, Visclosky is by far the longest-serving current member of Congress from Indiana.

He is a senior member of the powerful House Appropriations Committee but announced last month that he wouldn’t seek the panel’s chairmanship following current leader Rep. Nita Lowey’s decision to retire after next year.

U.S. Sen. Todd Young, Indiana’s senior senator, called Visclosky “a tireless advocate for Hoosiers in Northwest Indiana.”

“His list of accomplishments is long, and his impact will be felt for years to come. I’ve had the privilege to work with Pete to make Indiana Dunes our state’s first National Park, move the West Lake Corridor and South Shore Expansion projects forward, and more. I thank Pete for his service and wish him the best,” said Young, a Republican.

Visclosky’s decision to retire likely will set off a scramble of Democrats seeking the 1st District seat in Indiana. The district has been represented by a Democrat since 1931, and Visclosky never won a general election with less than 56% of the vote.

Hammond Mayor Thomas McDermott Jr. already has announced his plans to run for the seat.

“I’m sure the election will feature plenty of extremely qualified democratic candidates, all seeking to represent Northwest Indiana,” McDermott wrote in a Facebook post. “Regardless of who runs against me, I’m prepared to show the residents of Indiana’s CD1 that I will fight for this office like I have fought over the years for Hammond, an indication of how hard I would fight for them if I am elected Congressman.”

North Township Trustee Frank Mrvan also threw his hat in the ring on Wednesday.

“I believe that a public servant’s job is to do there very best to create an economy that works for everyone. I understand we must fight for the domestic steel industry against illegal imported steel and unfair trade agreements. I also understand our government must invest in educational opportunities and job training programs to ensure that everyone’s talents are realized in order to benefit our region,” Mrvan said in a statement.

Mrvan’s father is longtime Indiana State Sen. Frank Mrvan Jr.