U.S. Sen. Jeff Merkley, D-Oregon, has announced he is abandoning his presidential hopes for 2020 and will instead run for re-election.

“My best contribution is to run for re-election and do everything I can to help the Senate be a full partner in addressing the problems before us,” Merkley said Tuesday in a video release.

Merkley, 62, was first elected to his office in 2008 and has been openly exploring a presidential candidacy for the last year-and-a-half. He’s made several visits to Iowa and New Hampshire and other early primary states while presenting himself as a progressive with “bold” policies who remains true to his blue-collar roots.

A major dilemma is that the wide-open Democratic primary is occurring as his senatorial term is running out, he said.

He discussed the possibility of seeking a change in Oregon election law to run for both offices simultaneously, something that is allowed in several states. But he said he gave up on that idea after it got a negative reaction from Senate leaders.

“The underlying things that I’ve been wrestling with are what are the big battles worth fighting and how can I be most effective in contributing to the effort?” Merkley said. “I’ll be on the battlefield, but I’ll be on the Senate battlefield.”

There’s also the issue of being financially competitive in a Democratic race.

Many have large national followings that have enabled them to reap millions of dollars in support for a run at the presidency.

Vermont Sen. Bernie Sanders — who Merkley endorsed in 2016 — reported raising $6 million in the first 24 hours after announcing his latest run for president last month. Others with strong fundraising arms include Senators Kamala Harris of California and Elizabeth Warren of Massachusetts.

In his video, Merkley talked about growing up in a working-class home, being the first in his family to go to college — and how he still lives in a blue-collar neighborhood in east Portland.

He also addressed challenges he says the country needs to tackle: climate change, protecting the right to vote and rebuilding an economy that allows for widespread prosperity.

“I do admire many of the people who are running,” Merkley said. “There’s a lot of talent on the field. I really hope to do whatever I can to get them to take on and have a strong strategy on these three big challenges I’ve laid out, and perhaps I’ll endorse, but that’ll be much later in the process.”