After the success of the global Women's March, scientists are planning to send a message of their own to Donald Trump - there are no "alternative facts" when it comes to issues like climate change.
A date's yet to be set for the march, but hundreds of thousands have already expressed interest in attending. Two groups have been set up on Facebook - one public with 150,000 members and a private group, with nearly three times as many.
More than 171,000 people followed @ScienceMarchDC on Twitter in a matter of hours.
"There are certain things that we accept as facts with no alternatives," March for Science organisers say on their website.
"The Earth is becoming warmer due to human action. The diversity of life arose by evolution. Politicians who devalue expertise risk making decisions that do not reflect reality and must be held accountable. An American government that ignores science to pursue ideological agendas endangers the world."
Organisers say "anyone who values empirical science" is welcome to take part.
"That's the only requirement."
The march appears to have been triggered by a post on link-sharing website Reddit, in a discussion about the Trump administration's removal of any mention of climate change from the White House's website.
In the last week, Mr Trump has ordered all research by the Environmental Protection Agency (EPA) to be screened by political staffers before publication, including any information it posts on its website and social media pages.
His administration has also cracked down on social media posts by National Parks employees, prompting the creation of a number of "rogue" accounts such as @RogueNASA and @altEPA.
In the past, Mr Trump has called climate change a hoax "created by and for the Chinese in order to make US manufacturing non-competitive".
While the official website doesn't mention Mr Trump and says the march is "non-partisan", both the public and private Facebook groups say it is "in protest of the policies of the United States Congress and our President Donald J Trump".
Scientists find unlikely allies in the Juggalos
Another march is also planned, though perhaps a little less highbrow. Cult rappers Insane Clown Posse and their fans, known as the Juggalos, will storm the capital on September 16.
"This is the day that we are asking every single Juggalo to join us in our nation's capital, Washington, DC, to make a collective statement from the Juggalo Family to the world about what we are and what we are not," the duo said.
"We must collectively show them that we truly are a family that is united by a shared love of music and fellowship."
Insane Clown Posse have a beef with the federal government, having gone to court over the FBI's classification of the Juggalos as a "loosely organised hybrid gang".
The group sued the FBI, at first unsuccessfully but eventually winning the case on appeal.
"Over the past five years, our legal team has heard testimonies and reports from Juggalos all over the nation who have lost custody of their children, been fired from jobs, denied access into the armed forces, and the most common consequence - being officially labelled as a gang member by law enforcement agencies for wearing Juggalo-related clothing or brandishing one or more Juggalo tattoos."
A free concert featuring the group, Vanilla Ice and 2 Live Crew will be held afterwards.