White supremacist activists emboldened by Donald Trump’s stunning victory in this year’s presidential election warned that they would revolt if Trump continues balking on keeping his pre-election promises.

Leaders of the alt-right movement, who openly align themselves with racist Eurocentric ideals, told The Guardian that Trump denouncing white nationalism definitely would cause disappointment and disillusionment among members of the far right. These same supporters, who were seen raising their arms in the Nazi salute and chanting ‘Heil Trump!’ at a gathering just last month, vowed to fight back if the president-elect failed to meet their expectations.

White nationalist organizations like the National Policy Institute, headed by controversial leader Richard B. Spencer, had hoped they would enjoy some proximity to power with Trump in the White House. But the former real estate tycoon’s tendency to go back on his word and his reluctance to back the alt-right’s racist ideals is threatening the movement’s slow rise to prominence, leaders asserted.

White nationalist Jared Taylor, who runs the “race realist” magazine “American Renaissance,” was quick to point out that Trump had already backtracked on his promise to deport every undocumented immigrant from the U.S. The betrayal has some worried that this is just the first of many broken promises to come from the president-elect.

“In January, Trump will start governing and will have to make compromises,” said David Cole, a self-avowed Holocaust revisionist and writer for Taki’s Magazine. “Even the small ones will trigger squabbles between the alt-right. ‘Trump betrayed us.’ ‘No, you’re betraying us for saying Trump betrayed us.’ And so on.

“The alt-right’s appearance of influence will diminish more and more as they start to fight amongst themselves.”

Trump’s strong ties to the white nationalist movement, solidified by conservative views on issues like illegal immigration, miscegenation and political correctness, helped to electrify support from members of the racist groups, who voted to put him in office. However, Peter Brimelow, founder of the alt-right web magazine VDare.com, warned that Trump’s failure to deliver “important bones” could prompt severe backlash.

“I think the right of the right is absolutely prepared to revolt,” he said. “It’s what they do.”

According to The Guardian, the threat of rebellion comes even after alt-right leaders asserted that the white nationalist movement could grow and gain traction with or without Trump in office. The president-elect has since moved to appoint Steve Bannon, the former head of alt-right news site Breitbart, to his Cabinet as chief strategist, but white supremacist supporters still aren’t sure if he really has their interests in mind.

“Donald Trump was never a racial dissident of the sort that I am,” Taylor said. “He was never one of us. He’s an American nationalist. The left was wrong to think that he was dancing to the tune of people like myself.”

“Racial nationalism has not triumphed in America,” he continued. “It will someday. But to think it has done so [already] is delusive.”

Trump has not yet commented on the alt-right’s warning.