Depends on what is being subpoena’d. If it involves national security matters, or if it involves attorney-client matters, or such, it would require a SHOW CAUSE for the need. Fishing expeditions can never be any good and that is why we have SCOTUS.
Otherwise any partisan House of Reps can begin a fishing expedition against any president they hate, and just impeach him and negate the votes of half of the country.
They subpoenaed tax and loan records that date from prior to Trump becoming president.