POTUS did not want a political rival investigated; POTUS wanted a former VP investigated on probable cause of corruption/criminality.
Biden pursuing the Presidency is chronologically secondary & does not insulate against consequences of any wrongdoing.
Moreover, Biden's political aspirations do not thwart Mutual Legal Assistance In Criminal Matters (U.S./Ukraine Treaty).
Additionally, if there is not misconduct, the accused should want the truth out to clear suspicion.
If there is misconduct, and especially if Biden uses the U.S. taxpayer as an ATM, wouldn't we ALL want to know that?