This has turned out to be the week not to run for president.
Oregon Senator Jeff Merkley, former nominee Hillary Clinton and media billionaire Michael Bloomberg have all ruled out 2020 campaigns. (Mrs Clinton’s aides are trying to walk her statement back, but no one seems to believe them.)
Now Sherrod Brown joins them on the sidelines.
“I will keep fighting for all workers across the country,” Mr Brown wrote in a series of tweets on Thursday. “And I will do everything I can to elect a Democratic president and a Democratic Senate in 2020. The best place for me to make that fight is in the United States Senate.”
While the announcements by the other three – with the possible exception of Mr Bloomberg – prompted choruses of “yeah, of course” from the kind of people who follow these things, the reaction to the Ohio senator’s decision has been more along the lines of “WHAT, REALLY?”
Mr Brown was the kind of candidate who might have won the Democratic nomination – and the presidency.
He had been toying with a run since his re-election to the US Senate last November. He just concluded a “Dignity of Work” tour through key Democratic primary states. He embraces a for-the-working-class rhetoric that could have been a compelling counterpoint to Donald Trump’s conservative populism.
And his resume, as a politician who has thrived in a trending-conservative Midwestern state, seemed tailor-made for success in a presidential election that could hinge on who wins places like Wisconsin, Michigan and Pennsylvania.
If the best hope for Democrats in 2020 is rebuilding their electoral “blue wall” that crumbled in 2016, Mr Sherrod would have been a natural bricklayer.
It was not to be, however.
In announcing his decision, Mr Brown expressed optimism that his fight for the “dignity of work” will be taken up by other 2020 Democratic candidates.
More on the 2020 race
Expect every presidential campaign to claim the Ohio senator is referring to them.
They’ll surely argue his decision is good news for their candidate – a reflection of the Ohioan’s difficult-to-pigeonhole brand of politics.
His criticism of free-trade deals sounds almost Trumpian, but he also frequently denounces Wall Street and big financial conglomerates.
While he has been in favour of Democratic healthcare reform efforts, he hasn’t backed calls for government-managed universal healthcare. He talks more about encouraging work than fortifying the welfare state.
Minnesota’s Amy Klobuchar may now try to lay claim to the entire Midwest as her home turf. Former Vice-President Joe Biden could see this as clearing a path for the kind of blue-collar, moderate race he seems poised to launch.
Bernie Sanders backers might think their guy will have an inside track on key support that could have gone to Mr Brown.
“Brown would’ve complicated a lot of union endorsement processes, especially in the Midwest, potentially siphoning critical support from Bernie,” tweets progressive journalist Michael Tracey. “So his decision not to run is a testament to Bernie’s strength.”
In a November profile, the New York Times wrote that the gravelly voiced Ohio senator might be “a viable, and younger, alternative” to candidates like Mr Biden and Mr Sanders.
Without Mr Brown in the race, Democratic voters won’t have that option.
One man who undoubtedly has cause to celebrate, however, is Democratic Senate minority leader Chuck Schumer.
If Mr Brown had run, and won, Mike DeWine – the Republican governor of Ohio – would have chosen his replacement, flipping a seat that could stay in conservative hands for a long time.
Mr Schumer’s hopes of becoming Senate majority leader in 2020 would have taken a serious blow.
“The question hanging over Brown isn’t whether he’s a good candidate, or even a great one,” wrote Slate’s Jordan Weissman back in November, when the Brown buzz was first building.
“It’s whether he’s so much better than the other 2020 contenders that it would be worth waving his Senate seat goodbye.
Democrats won’t have to worry about that particular conundrum now.
Mr Brown will continue to defy political gravity in his home state for at least six more years, while other candidates fight it out for the top prize.
Who will take on Trump in 2020?
No Sherrod Brown in the race to stop Donald Trump from being re-elected. But who else has a shot at becoming the next president?