If this were a Democrat as President, we'd be seeing impeachment, and not just "critics say"
A Democratic president would be facing impeachment votes at every opportunity regardless of what they did. The MAGA party (formerly the Republican party) is no longer a legitimate political movement in the confines of rules and norms. They are a rogue fascist element that seeks the seizure of total power as quickly as possible. They are at war with all of us and they are winning, in part because the mainstream refuses to act like we are at war.
Pardoning Nixon did lasting damage to the union, of which we are suffering the consequences right now, so no.