On Monday morning, after two days of flailing around with ambiguous statements, President Donald Trump finally denounced the racist violence that led to the death of a counter-protester in Charlottesville, Virginia. “Racism is evil and those who cause violence in its name are criminals and thugs, including the KKK, Neo-Nazis, and white supremacists,” Trump remarked in a prepared statement. The words themselves were unremarkable, but it’s astounding that it took a behind-the-scenes struggle to get Trump to utter them, after he had weaselly blamed “many sides” for the fatal violence.

There are several possible explanations for Trump’s reluctance to condemn racism, starting with the fact that the president is personally a racist, as evident by his long history of housing discrimination and incendiary remarks, including his lead role in promoting in birtherism. More strategically, Trump might have feared alienating white nationalists who supported him in the election.

But a bizarre memo from a fired National Security Council official, made public on Thursday by Foreign Policy, offers a window into the larger ideology that makes Trump so loath to say anything critical of white supremacist groups. The memo, written in May by NSC official Rich Higgins, who was later fired, blames “cultural Marxism” as the root ideology animating political opposition to Trump.

“This is not politics as usual but rather political warfare at an unprecedented level that is openly engaged in the direct targeting of a seated president through manipulation of the news cycle,” Higgins wrote. “It must be recognized on its own terms so that immediate action can be taken. At its core, these campaigns run on multiple lines of effort, serve as the non-violent line of effort of a wider movement, and execute political warfare agendas that reflect cultural Marxist outcomes.” According to Higgins, “cultural Marxism” is either allied with or animating such disparate anti-Trump forces as Islamists, Black Lives Matter, the ACLU, the Council on American-Islamic Relations, the Muslim Brotherhood, the academy, the media, the Democratic Party, globalists, international bankers, late night TV comedians, the “Deep State,” and moderate Republicans.

The memo has been immensely polarizing within the Trump administration. National Security Advisor H.R. McMaster forced Higgins out over the memo, but Trump reportedly was a fan of it. As Foreign Policy reports: