THere can’t be a threat if the people being threatened do not know of the threat.
There can be no quid pro quo if there is no quo.
This may be the single biggest under-reported fact in the impeachment scandal: four months before Trump and Zelensky had their infamous phone call, Ukraine law enforcement officials officially reopened their investigation into Burisma and its founder.
Kind of pointless trying to intimidate someone into something they were already doing. In the linked thread another excellent point was made: Biden did not really want to run but once he found out the anti-corruption Ukraine candidate won 4 days later he announced his run: No doubt so he could use the excuse about being a political target. Biden is stuipd but is he so dumb that he would brag about his crime on camera unless he figured at the time he was no longer going to run for anything?