3 of 3 Generalized the question because it is not specific to any particular president.

Is there a way the US president could extend his immunity in the future?

"However, the Court ruled in Clinton v. Jones, 520 U.S. 681, 117 S.Ct. 1636, 137 L.Ed.2d 945 (1997), that a sitting president does not have presidential immunity from suit over conduct unrelated to his official duties. The holding came in a civil suit brought by Paula Corbin Jones against President Clinton." (U.S President legal definition of U.S President)

Is there a way a sitting president could extend his immunity in the future? For example, to also cover his activities as owner of private companies?