That’s because Trump’s appearance on the NBC show has triggered a seven-day window where rivals can request equal airtime on the channel. Trump’s total time onscreen, which came in at around 12 minutes, was first filed to the Federal Communications Commission by NBC’s New York affiliate, WNBC TV.

First reported by Variety, this rule under Section 315 of the Communications Act is commonly known as the “Equal Time Rule” and was drafted into the Act so radio and TV stations would be unable to influence elections by refusing airtime to candidates of their choosing.

Anyone interested in equal time has to show they are viable, bona fide candidates running in the race. NBC is not required to put them in the same program, but candidates like Marco Rubio and Jeb Bush may consider trying to host a future episode—Trump’s SNL showing scored the highest ratings for the program since 2012.