The South did not secede to keep the slavery system growing inasmuch to keep it stabilized. The South/CSA actually banned the African Slave Trade/importation of slaves as one of its 1st acts. The idea that the South 'went to War' as the aggressor is highly debatable ie. Virgina did not secede until after Ft. Sumpter - and Virginia's logic was that it opposed Union troops crossing its borders for the purpose of coercing/making war against another state. Slavery was practically already at an end in Virginia and was being phased out.
Lincoln's racism? I would say Lincoln was personally more racist than Jefferson Davis ie. Lincoln repeatedly referred to 'slaves' and 'Africans' as an 'inferior race' - and he stated repeatedly that the 'South is doing what we would do if we were in their place...' Lincoln's wife was from a slave-holding Kentucky family. In contrast, Jefferson Davis adopted a 'mulatto'<sp>child named Jim/John Limber whom he treated as his son. Davis' plantation in Mississippi was later used by the Freedman's Bureau because it was deemed to be a model community. The Davis family had designed it so as to assist 'slaves' to develop trades, have their own shops and community/courts...so they could be successfully freed and integrated into society. Jefferson Davis' brother had actually met with Robert Owen<a uptopian socialist>to design the community. Jefferson Davis was married to the granddaughter of a New Jersey governor. The C.S.A.'s vice president , Alexander Stephens<sp> opposed secession in 1860. Stephens was in fact a rabid racist. The irony is that he argued against secession in 1860 because he believed his close personal friend Abraham Lincoln shared his racist views and would not destabilize the South via reforms that were too radical.
Part of the problem the South faced with slavery is that cities like Charleston and New Orleans actually had larger slave populations than white pouplations - so the idea of suddenly turning over such places to suddenly freed slaves - was a very difficult and chaotic concern. The South also had larger freedmen populations too.
Part of the problem was that slaves and slave owners were locked together. It's easy to say 'Free the Slaves' - but the practical aspects of doing so are not so easy ie. 'Where do they go?' 'How do they economically survive?' The slavery system was an archaic welfare system. In 1860 a young adult male slave cost what would today be the cost of a brand new top of the line Mercedez Benz. Plantations were often 'land poor' and their credit/$ was woven in the appraised value of 'slaves.' Slave owners were often obligated to the care and liabilities of their slaves. Davis viewed the problem through Southern eyes and favored the gradual ending of slaves - as well as some repatriation schemes - as did Lincoln! Lincoln was not a radical abolitionist.
Davis wanted to expand slavery into Western states so as to dilute it while still protecting the stratification of Deep South states, so as to not destabilize the South. Lincoln opposed such expansion and favored Northern Free State hegemony, which the South distrusted because it meant Northern States could in essence disrupt the South and exploit it. Most Supreme Court Judges, Diplomats, and U.S. Presidenthad been overwhelmingly mostly southerners until 1860.
I believe Lincoln was a Great President. He was a true leader, but I also believe he was not a saint, and a lot of the 'Father Abraham mythology' is not deserved. I tend to view Jefferson Davis as a great leader. There were many aspects of Davis' character that were similar to Lincoln's. By the end of the War, Davis suffered from chronic stress related migraine headaches and neuralgia. He was practically blind in one eye. He had a daily medical regimen of 'castor oil, a grain of opium, chalcocum wine<for gout>and he inhaled burning rosemary leaves for his intense headaches... He lost one son - a small child who fell off a balcony in a tragic accident. And at the end of the war he lost Jim Limber who was torn from the Davis family by a Union soldier. Limber was pleading an screaming for Davis...as he was taken away... For over almost two years Davis was held in solitary confinement, and his guards were instructed to never speak to Davis.The young officer in charge of Davis was later involved in some of the worst massacrs of native Indian tribes in American history.
Davis was a great man and so was Lincoln, but they were men of their times. The political relationship between Davis and Judah Benjamin might be realistically seen as similar to that between Bismark and Bleischroeder - Old South and New South like Old Prussia and the New Germany/Austro-Hungary.
Looking at the charactor of Lincoln and Davis - I'd say the worst president was Buchanan. He left'em a big mess. In contrast to Lincoln and Davis - he was totally inept and passive. When he left office, it was like he was fleeing.
He made Jimmy Carter look like Superman. Buchanan was very weak.
However, one could argue that he was actually in favor of Southern secession - and was trying to assist it via his inaction.