There is talk of Breitbart bureaus opening in Paris, Berlin and Cairo, spots where the populist right is on the rise. A bigger newsroom is coming in Washington, the better to cover a president-elect whose candidacy it embraced.

Mainstream news outlets are soul-searching in the wake of being shocked by Donald J. Trump’s election last week. But the team at Breitbart News, the right-wing opinion and news website that some critics have denounced as a hate site, is elated — and eager to expand on a victory that it views as a profound validation of its cause.

“So much of the media mocked us, laughed at us, called us all sorts of names,” Alexander Marlow, the site’s editor in chief, said in an interview on Sunday. “And then for us to be seen as integral to the election of a president, despite all of that hatred, is something that we certainly enjoy, and savor.”

Breitbart not only championed Mr. Trump; its chairman, Stephen K. Bannon, helped run his campaign. On Sunday, Mr. Trump named Mr. Bannon as his chief White House strategist and senior counselor, further closing the distance between Breitbart’s newsroom and the president-elect.