On election night at Donald Trump's victory party, a jubilant Milo Yiannopoulos paraded through the press section with a beer in one hand, an ice cream bar in the other, and a videographer in tow. Turning to face the camera, he declared that Breitbart News is an “influential, now-mainstream publication.”

It was an odd boast about a website described in August by former chairman Stephen K. Bannon as “the platform for the alt-right” — a site whose influence grew out of a proud and aggressive rejection of the mainstream. Yiannopoulos probably just meant that Breitbart's many critics will have a hard time dismissing the site after Trump's win. Yet Breitbart has, in fact, looked increasingly mainstream since Election Day.

Besides Bannon, now a senior White House adviser, two other Breitbart staffers will reportedly join the Trump administration in precisely the kind of “incestuous merging of media, journalism and politics” that former Breitbart editor Larry O'Connor has said the site is supposedly against.

Meanwhile, Breitbart has made several recent hires from decidedly mainstream news outlets: John Carney from the Wall Street Journal, Sam Chi from RealClearPolitics and Kristina Wong from the Hill. Their mainstreamitis is bound to infect the Breitbart newsroom.

And Yiannopoulos, Breitbart's best-known writer and provocateur, appears to be toning things down as he works on a book for which he reportedly received a $250,000 advance. Yiannopoulos bragged to the Hollywood Reporter in December that he “met with top execs at Simon & Schuster earlier in the year and spent half an hour trying to shock them with lewd jokes and outrageous opinions.”

“I thought they were going to have me escorted from the building, but instead they offered me a wheelbarrow full of money,” he said.

Simon & Schuster offered a very different account of the meeting in a letter sent Monday to other authors in the publisher's stable, some of whom had protested the decision to sign Yiannopoulos, who was permanently banned from Twitter in the summer. According to Simon & Schuster chief executive Carolyn Reidy, Yiannopoulos actually “said that he was interested in writing a book that would be a substantive examination of the issues of political correctness and free speech.”

Reidy added that Simon & Schuster will not publish hate speech and that Yiannopoulos will have to adhere to the publisher's standards. The book's title, “Dangerous,” is a censored version of Yiannopoulos's self-applied moniker, “dangerous f----t.”

“This book,” Yiannopoulos told the Hollywood Reporter, “is the moment Milo goes mainstream.”

There's that word again. Yiannopoulos and Breitbart are, of course, free to capitalize on their support of Trump's successful campaign and to try to broaden their audience. But if they want to go mainstream, they risk alienating readers who were drawn to the website because it seemed to be by and for outsiders.

This is the same conundrum that confronts indie bands and craft beer makers — get too popular, and you might lose your street cred.

I asked Breitbart's Washington editor, Matt Boyle, whether he is concerned about maintaining the site's rebellious brand. He didn't respond.

If Boyle and his colleagues aren't thinking about the ramifications of all this mainstreaming, they should be. The hard-right readers who view it as their platform might use a different term: selling out.