Julianne Moore, Bryan Cranston, Kerry Washington, Mark Ruffalo, Neil Patrick Harris, Lena Dunham and Macklemore are among more than 100 celebrities who have joined a campaign to urge Americans to deny Donald Trump the White House.
The campaign is part of MoveOn.org Political Action's #UnitedAgainstHate campaign.
"We believe it is our responsibility to use our platforms to bring attention to the dangers of a Trump presidency, and to the real and present threats of his candidacy," says an open letter signed by the celebrities.
"Donald Trump wants to take our country back to a time when fear excused violence, when greed fueled discrimination, and when the state wrote prejudice against marginalized communities into law .... Some of us come from the groups Trump has attacked. Some of us don't. But as history has shown, it's often only a matter of time before the 'other' becomes me."
Among the communities it says Mr Trump has attacked are Mexican and Latino people, black people, LGBT people, women and their healthcare providers, Asians, refugees, people with disabilities, working class people, American prisoners of war, and others.
"We call upon every American to join us," the letter says, "to stand together on the right side of history, to use the power of our voice and the power of our vote to defeat Donald Trump and the hateful ideology he represents."