Maybe a better comparative analogy would blaming Lincoln for Confederates' assault on Fort Sumter is like blaming President Johnson for the North Vietnamese firing on the Turner Joy...
Well.... I supported Goldwater that year, and we were told that if we voted for Goldwater, there would be war in Vietnam and riots in the streets at home, plus other terrible things...
Sure enough, that's just what happened. ;-)
In fact, there were Gulf of Tonkin incidents, exaggerated by both sides for their own purposes.
North Vietnamese claimed to have hit the USS Mattox with a torpedo and shot down one US aircraft.
President Johnson (need I say it: a Texas Democrat?) and Congress (need I say it: ruled by Democrats?) responded by authorizing war in Southeast Asia.
Both came later to regret that decision, but at the time it seemed entirely necessary, regardless of how major or minor the Gulf of Tonkin Incident itself was.
By stark contrast, there is no historical dispute whatever over the Confederate assault on Fort Sumter.
It certainly happened, US troops surrendered and the entire Confederacy was delirious with joy over the results.
It caused four more states to switch from Union to Confederacy -- Virginia, North Carolina, Tennessee and Arkansas -- doubling the Confederacy's white population.
Sumter was a huge success for Jefferson Davis.
Neither is there any dispute that the Confederacy's assault on Fort Sumter was a clear act of war -- as clear as the Japanese attack on Pearl Harbor.
Any possible doubt was removed when the Confederacy soon formally declared war on the United States, May 6, 1861.
After that, the Confederacy and slavery's fate was sealed, given the Union's resolve for victory.