Applications for naturalization (on Form N-400) can suffer from the same delays that other immigration applications endure. But for N-400 applicants who finished their interview, Section 336(b) of the Immigration and National Act, 8 USC § 1447(b), provides for a very specific (and powerful) cure.
According to the statute:
If there is a failure to make a determination under [INA] § 335 [8 U.S.C. § 1446] before the end of the 120-day period after the date on which the examination is conducted under such section, the applicant may apply to the United States district court for the District in which the applicant resides for a hearing on the matter. Such court has jurisdiction over the matter and may either determine the matter or remand the matter, with appropriate instructions, to the Service to determine the matter.
Basically, if an N-400 decision isn’t made within 120 days of the initial interview, applicants can go straight to a federal judge who can either decide the merits of the application (approve or deny it) or send it back to USCIS with instructions. For instance, the court can order USCIS to decide your application within a certain amount of days. As a tool for fighting immigration delays, this is a particularly powerful one since it can take decision-making authority away from USCIS. Because circumstances differ, it’s best to consult with an experienced immigration litigator when considering this strategy.