They can compel people to talk to them and produce records, subject to the protections witnesses have in court. But they cannot make an agency do anything. They can, however, make their reports public. Aside from choosing what questions to ask and issuing subpoenas, their powers are mainly persuasion and publicity. An ombudsman generally does not have the power to investigate the people who appoint the ombudsman and other elected officials, and does not have the power to look at the judicial acts of courts.
Voters have remedies such as recall or impeachment for elected officials.
Unfavorable court decisions can be appealed to a higher court. Complaints about judicial misconduct may result in an administrative sanction of a judge or rejection of an incumbent at the polls. The ombudsman is not an alternative to these traditional remedies. This varies according to the law creating an office. For a general jurisdiction Ombudsman, the administrative acts of most, if not all, agencies in a local or state government are within an ombudsman's mandate.