Its § 315 of the Communications Act of 1934. The Trump ad is gross, but Randall Terry, the Constitution Party candidate has also been using the rules to run a very graphic (anti-abortion) ad titled "Kamala Horror" But to answer your question: Yes. N word, profanity...campaign ads must run as is.

I still say Kamala should run an ad with Stern endorsing her with a shit load of profanity. “She’s the best fucking candidate”. Would be fabulous. But she won’t do that.

a woman in a polka dot shirt and a purple jacket is smiling

ALT: a woman in a polka dot shirt and a purple jacket is smiling

Here's a piece I wrote on equal time (also part of Section 315) scholarship.law.edu/cgi/viewcont...scholarship.law.ufl.edu/cgi/viewcont...