There are two types here: (1) Pardons for crimes not yet committed. (2) Pardons for crimes committed, but not yet convicted. The first type will allow the pardoned to commit a crime in the future for free, which obviously should not be allowed. The second should be allowed if we have this pardon system at all.
The second type became a political necessity, for example to protect Liz Cheney from a vengeful administration.
(2) Do you mean not yet charged or not yet convicted ?
Because I can get you would want to shield some people from persecutions (just or unjust) from your successor, but I see no reason why you would be able to pardon someone charged but waiting for trial. This makes a mockery of justice, the public can't discover the facts but more importantly: why pardon someone that is still considered innocent ?
> The second type became a political necessity, for example to protect Liz Cheney from a vengeful administration.
Was it, though? It struck me as more empty political theater around an event largely defined by political theater.
> a political necessity, for example to protect Liz Cheney
IANACL but surely there are other ways to protect people from politically motivated prosecutions? E.g. jail anybody attempting to direct the DOJ for personal or political reasons?
The notion itself that someone needs to be protected by a 'vengeful administration', while judicial system should be not politically affiliated is telling how broken the whole separation of powers is. Everyone who is a ruling party puts candidates they know aligned with their views, resulting in 'just wait until my turn comes and I will do as much as damage as possible' cycle.