When it comes to getting a new trademark of the phrase for use on clothing, though, Nike isn’t having it. “Opposer has continuously used the JUST DO IT Mark in interstate commerce since at least as early as 1989 in connection with various clothing items,” they write. The argument is, basically, that the marks are too similar, are likely to cause confusion and that Nike has won similar cases in the past. Somewhat amusingly, one of the cases Nike cites is one where they successfully blocked the registration of a trademark for “Just Jesu It.” Yes, as in The Jesuits.
While it likely has nothing to do with this trademark opposition, it’s worth noting that WWE is an equity partner in TapOut, the mixed martial arts lifestyle brand turned athletic apparel company. So they now compete with Nike in ways they did not before.