Is it possible to change the DOJ policy on not indicting a sitting president?

Massachusetts Senator and Democratic presidential candidate Elizabeth Warren wants to change the Justice Department’s current policy of not indicting a sitting president. Special Counsel Robert Mueller said this policy is why he didn’t recommend an indictment of President Trump.

Also, the Supreme Court has already heard arguments about whether the citizenship question can be allowed on the next Census. New evidence came to light last week about Republican efforts to draw legislative boundaries based on eligible voters, not the total population. But it’s unclear whether the Supreme Court will consider it.