Ruth Ben-Ghiat is a professor of history and Italian studies at New York University. She is a frequent contributor to CNN Opinion. The opinions in this commentary are hers.

Positioning himself as the defender of victimized white males, he goes after those he sees as their antagonists: feminists, people of color, and immigrants, cloaking his hate speech under the mantle of the right to free expression. He's banned for life from Twitter (for his harassment of African-American actor Leslie Jones).

So why on earth would Simon & Schuster give him a platform?

Profit, for one thing. "Dangerous" immediately went to the top of Amazon.com's bestseller list on the strength of its pre-orders. The media opportunities generated by the publishing house's parent company, CBS, will likely compensate for any boycotts that materialize ( the Chicago Review of Books has announced it would not review any Simon & Schuster books in 2017 as a protest and others, from indie booksellers to celebrities, are talking about boycotts).

There's also the issue of freedom of speech. Opinion is divided, even among liberals, about whether Milo, and his book, should be censored. Where are the boundaries about what's fit for public circulation and who should decide or enforce them? This same debate arose last year in Germany on the occasion of the reissue of Adolf Hitler's Mein Kampf, which had been banned in Germany since the end of World War II. For every reader who came away from reading it disgusted by the violence of fascism, the concern was that there could be others inspired by exactly that.

In the United States, many of Milo's fans are also supporters of President-elect Donald Trump. Milo sees Trump the political disrupter as a kindred spirit. As he noted at the opening of the art show #DaddyWillSaveUs (during which he sat almost naked in a tub full of cow blood to honor Americans killed by undocumented immigrants), Trump's "Make America Great Again" has revived "the dissident element in culture -- punk, mischief, irreverence..." Such boosterism apparently made Milo a good fit for Simon & Schuster's Threshold imprint, which publishes not only Glenn Beck and Rush Limbaugh but also Trump himself (most recently "Great Again: How to Fix our Crippled America"). By signing Milo's "Dangerous," the publishing house simply makes more evident what Trump's campaign already proved: for today's GOP, racist rhetoric has become normal political discourse.

The risk that hateful rhetoric could become an inspiration for rather than a deterrent against hateful action is particularly relevant in Milo's case, since his behavior raises the question of the link between dangerous speech online and on-the-ground actions -- a connection that came up repeatedly during our recent Presidential campaign.

Milo is above all a performer who lives for the attention -- in the form of outrage -- his theater of bigotry brings. At the University of Wisconsin (a stop on his "Dangerous Faggot" college campus tour), Milo harassed a transgender student in person; at DePaul University, he claimed he had had sex with the brothers of his black female protesters and called for their arrest. Nothing's off limits to Milo, and his fans like it that way.

And this is the real storyline of Milo's book deal: far from being "mischievous," Milo is a barometer for the far rightward shift and expansion of the conservative movement in America to elevate figures that traffic in violent speech.

In fact, if we look closely, Milo and Trump have more in common than one might think. Both have outsized egos and platforms but have chosen to target ordinary citizens on Twitter, leading in some cases to their followers issuing threats to their targets' safety (including rape, if that target is a woman).

Both mock those who are "different" (Trump, the disabled; Milo, transgender people). Both are longstanding misogynists. Both continually test their audiences to see what they can get away with and believe the rules won't apply to them.

So while Milo may seem a unique figure, in reality he merely serves up, with the flash of excess and a British accent, the attitudes toward people of color and women that marked the Trump campaign.

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Lest you doubt that, listen to Milo, and then revisit the videos of Trump's campaign rallies. See the faces contorted with hatred, and listen to the chants wishing violence on his opponent, Hillary Clinton. Watch as Trump supporters whose skin is too dark for the crowd's liking are manhandled and ejected, as happened in North Carolina and elsewhere.

We can debate endlessly the logic or morality of Simon & Schuster's giving Milo a lucrative deal, but ultimately the responsibility for the climate that made this professional hater a bankable figure is the GOP's, and Trump's, own.