Sen. Jeff Merkley said he had to make a decision between the Oval Office or the Senate.

PORTLAND, Ore. — Sen. Jeff Merkley announced early Tuesday morning that he will not run for president in 2020.

In a campaign-style video announcement, Merkley said it's important to have strong leadership not only in The White House, but also in Congress. He said he will run for re-election in 2020.

"I believe that there are Democrats now in the presidential race who are speaking to the importance of tackling the big challenges we face," Merkley said.

"But what I'm also sure of is that, right now, the Senate is not prepared to be a full partner in this fight. My best contribution is to run for re-election and do all I can to help the Senate be a full partner in addressing the challenges before us." Merkley said.

Earlier this year, Merkley said he was weighing whether he could be more effective as a senator or a presidential candidate.

Washington Gov. Jay Inslee last week announced he will seek the 2020 Democratic presidential nomination.

Mekley says he now aims to fight anti-democracy moves including voter suppression, gerrymandering and dark money. He said he also wants to focus on helping families by improving health care, education and access to living-wage jobs and on stemming climate change.

“These are the things we feel like we have to take on, and we have to take them on boldly and aggressively,” Merkley said.

He is not endorsing any candidate yet but said he is impressed by many of those Democrats who have already declared their candidacy or intention to run.

“If you’re running, you’ve got to present a credible and determined vision on how you’ll take on these problems,” he advised the growing field.

In just the past few days, former Colorado Gov. John Hickenlooper and Inslee launched their presidential bids, and Hillary Clinton and former Attorney General Eric Holder said they’re not running.

Merkley expressed guarded optimism that Democrats might regain control of the Senate in 2020, girded by opposition to President Donald Trump.

If the House were to impeach Trump, the Senate would act as jury in a trial overseen by the chief justice of the Supreme Court, and Merkley would have a seat in the juror box, something he indicated he anticipates happening.