Because “Look over there!” is the whole premise the the OP’s meme.

Bringing up the ex-President’s son prior drug problem while the current PEDOdent’s son is still a meth addicted ‘john’ is the very essence of the “Look over there” argument.

No, it isn't.

Wrong. It absolutely is.

Trump (and his family) are no longer in power, so any mention of them is a feeble attempt to deflect away from the Bidens and their faults.