And it was the exit of the Southern States from the Democratic Party that facilitated Lincoln's election.
Now, do you favor the idea that States can leave the Union if they don't agree with the outcome of a Constitutional process?
If the South "just wanted to be left alone", why did they ratify the Constitution and join the Union?
Nonsense. Lincoln offered every possible conciliation to the South with the exception of the only one that the South was truly concerned with --- the right to spread slavery to the entire nation. As a man elected on a Free Soil platform and with that platform absolutely dominating the election, Lincoln could hardly be expected to compromise on that issue. He vowed not to interfere with slavery where it existed. He promised to vigorously enforce the Fugitive Slave Act and respect the Dred Scott decision (both of which he believed to be unconstitutional and abhorrent laws) and he even promised to not force emancipation inside the District of Columbia, something he had strongly supported since his days in Congress. Expecting Lincoln to compromise on the expansion of slavery after he was elected on that very issue would have been like expecting Ronald Regan to come out in favor unilateral disarmament and massive tax increases after he was elected.
Outside the South, where anyone who voiced even the mildest criticism of slavery was considered to be a dangerous radical, Lincoln was seen as a moderate or even as being unfriendly to the true radical abolitionists who were Lincoln's harshest critics in the early years of his presidency. Even Stephen Douglass, the author of the Kansas-Nebraska Act which alienated much of the North, was considered by the South to be an unacceptable radical by 1860 since he supported the idea of popular sovereignty in the territories over what the South demanded -- the unconditional right to take slaves into the territories with or without popular consent. That is what split the Democrats in 1860.
There were plenty of radicals on both sides of the issues then, but none of them considered Lincoln to be a radical. By 1860, there was no possible compromise Lincoln could have made that would have stopped what was to come. Clay, Webster, Calhoun and finally Douglass had brokered every possible compromise over the previous 40 years. There was no room left for either side to maneuver. The "postponement" made in Philadelphia in 1787 in addressing slavery had finally run out as Jefferson and others predicted it would.
Then don't shoot up forts that don't belong to you.