Have you ever dwelled in thought on when the last US president actually governed?
Before the fall the Romans had four emperors, because one just couldn't manage the entire empire. Of course Constantine changed that, but he threw out the baby with the bathwater. He rewrote with one stroke the religion of Rome, then ditched Italy altogether for Byzantium. Overnight the empire went from being Roman to being Greek.
Lincoln didn't govern any more than Constantine did; he simply tore down the old house and built a new one.
Washington certainly governed; it was under his hand that the new nation actually became a nation rather than a proposal. How many after him actually governed? Grant certainly didn't. All he did was sit as those he trusted plundered all they could in his name.
Could it be that a US president can no more govern the US any more than one emperor could govern the empire?
I think perhaps.
Licoln wasn't a president in the sense that Washington was. Presidents are supposed to govern, not rule, and any who can't govern shouldn't be described as presidents (despite the fact that it is possible for such to occupy that office).
Therefore I contend that Lincoln wasn't the worst president. He wasn't a president at all.
Like George W. Bush and whoever may follow him. The presidency has become a hollow figurehead, waiting for a beast to occupy it.