Dana White is a combat promoter and the CEO of the Ultimate Fighting Championship. This implies that the adage “all publicity is good publicity” is often true.

However, the combative Trump ally could have overdone the saying with a straightforward welcome.

Andrew and Tristan Tate, the controversial internet personalities who recently left Romania after being prohibited from doing so due to criminal charges, including ongoing human trafficking, were on the other side of Mr. White’s handshake and embrace during his Power Slap event in Las Vegas on Friday. Late last month, the travel prohibition was lifted.

Mr. White is heard saying, “Welcome to the States, boys,” in a video of his encounter with the Tates that has gone viral.

The Tates went to U.F.C. 313 the next evening while attending another of Mr. White’s functions.

For those who say outlandish and perhaps offensive things, Mr. White has created a multibillion-dollar company. A perceptive cultural figure, he has contributed to the creation of a new, masculinist American mainstream in which celebrities, right-wing YouTubers, and big companies coexist together.

However, by accepting the Tate brothers, who have long been viewed as the misogynistic periphery of the so-called manosphere and charged with crimes against women, Mr. White has opened the tent so wide that even some well-known online bloggers who fervently support Mr. Trump have expressed surprise.