A. Congress can override the pardon by a 2/3 vote of both chambers. B. Presidential pardons can be overturned by a future president. C. Pardons issued by the president can be blocked by the courts (judicial review). D. Presidential pardons are absolute, and they cannot be overturned.
D, presidential pardons cannot be overturned by the courts or congress no matter how controversial. The power of a pardon was only given to the executive office per the constitution.