Today, with various legal issues swirling around Pres. Trump and his associates, there has been discussion on what legal action can or cannot be taken against a sitting president. Some argue that a sitting president can only be impeached and tried by the Congress. Some have suggested that is true for crimes committed while president, but not those before taking office. What can we divine from history?
When Pres. Nixon resigned and Vice Pres. Ford became president, Ford gave Nixon a blanket pardon for any crimes Nixon may have committed. This action would have been pointless if it was not possible to prosecute Nixon once he was out of office. After Ford was sworn in as president, Nixon was no longer a government official, so he could not be impeached - the pardon could only protect him from the criminal justice system. The pardon Ford gave Nixon was a "blanket pardon," so it might have applied to crimes Nixon committed prior to becoming president. However, the crimes Nixon was really being investigated for were those he did while president. It would seem that Nixon (and therefore former presidents in general) could be prosecuted in court for crimes committed while president.
But can a sitting president be prosecuted by the courts rather than the Congress?
The year before Nixon resigned, his first vice president (VP), Spiro Agnew resigned from office and, on the same day, pleaded no contest to federal charges of income tax evasion. The charge resulted from an investigation by the United States Attorney for the District of Maryland. In exchange for Agnew's plea, other charges were drompped which involved political corruption from which Agnew received payments both before and during his time as VP. This tells us that a sitting VP can be prosecuted by the criminal justice system (not just the Congress) for crimes, but it may not be clear whether that applies to those committed (1) before, (2) during or (3) both before/during time as VP. Since the corruption started before he was VP but also took place while he was VP, I'm not positive whether this example proves a sitting VP can be prosecuted only for crimes committed before being VP, only for crimes committed while VP, or for crimes committed at any time.
Article II, Section 4 of the US Constitution says, "The President, Vice President, and all civil Officers of the United States shall be removed from Office on Impeachment for, and conviction of, Treason, Bribery, or other High Crimes and Misdemeanors"
So, the example of Agnew seems to apply, since both president and VP are impeachable. If VP's weren't impeachable, then we might expect different rules for presidents and VP's in terms of prosecution by the criminal justice system.
It seems to me (a non-lawyer), that this tells us that Trump could be prosecuted outside of impeachment while he was in office. The only question seems to be whether the charges would have to be for crimes before he became president, for crimes while president or either. This may not be an obstacle. He may have been involved in collusion or other crimes (business or political) prior to being elected, and he may be guilty of obstruction of justice, influence peddling or other crimes while in office.
Hopefully, some prosecutors on a federal, state or local level will consider whether it is possible for them to apply this approach.
I don’t think there would necessarily be more publicity or time from a president’s workday for a criminal prosecution than for impeachment proceddings. So, I don’t think that should preclude this approach.