Stephen Miller is one of the most influential advisors in the White House. He has crafted Donald Trump's speeches, designed immigration policies that ban Muslims and separate families, and outlasted such Trump stalwarts as Steve Bannon and Jeff Sessions. But he's remained an enigma.Until now. Emmy- and PEN-winning investigative journalist and author Jean Guerrero charts the thirty-four-year-old's astonishing rise to power, drawing from more than one hundred interviews with his family, friends, adversaries and government officials, as well as years of reporting from the U.S. border. Radicalized during a rocky period in his youth, Miller relished provocation at his high school in liberal Santa Monica, California. He clashed with administrators and dark-skinned classmates over his invectives against bilingualism and multiculturalism. At Duke University, he cloaked racist and classist ideas in the language of patriotism and heritage to get them airtime amid controversies. On Capitol Hill, he served Tea Party congresswoman Michele Bachmann and old-school Alabama Senator Jeff Sessions.Recruited by Bannon, Miller met his idol: Donald Trump. Having dreamed of his presidency before Trump even announced his decision to run, Miller became his senior policy advisor and speechwriter. Together, they stoked dystopian fears about the Democrats, "Deep State" and "American Carnage" -- apocalyptic visions of migrants and their supporters as an existential threat to America. Through backroom machinations and sheer force of will, Miller survived dozens of resignations and encouraged Trump's harshest impulses, in conflict with the president's own family. While Trump railed against illegal immigration, Miller crusaded against legal immigration. He slashed refugee admissions to record lows, obliterated asylum and reduced green card access. Miller rallied support for this agenda, even as it triggered humanitarian crises and legal battles, by courting the rage that found expression in tragedies from El Paso to Charlottesville.Hatemonger unveils the man driving some of the most divisive confrontations over what America means--and what it will become.