He should lay low on this. As President, Trump will be able to have a good look at ALL of Obama’s past. The evidence is overwhelming that he is not even a US Citizen.
Once proven, every action of the usurper becomes null and void, including any pardons he issues. That my FRiends, is where the true swamp draining begins. Eight years of complete and massive corruption laid out in the sun to shrivel and die a proper death.
I don't know for sure about pardons in particular, but the time-honored legal rule is to invoke the ex officio rule. Unwinding all his acts would be too disruptive to even seriously contemplate. This has happened, although typically at lower levels, like mayors.
would love if we could undo BO’s SC appointments and many of their rulings.....but i won’t hold my breath