There's a tendency today to think of the Confederates as victims or as people like you and me. But Confederate elites, like all elites and more than some, were interested in power for themselves. They saw slavery as the basis of their civization, or of all civilization. They were convinced that slavery was threatened and that slave territory ought to be expanded. Indeed, many thought that slavery would die if it were geographically confined. Some dreamed of an American slaveholding empire stretching to include Mexico, Central America, or the Caribbean islands. And they had an exaggerated idea of the Western world's hunger for cotton and the power that it would give them. I don't think it's out of place to call them "extremists" or "radicals."
Of course there were others who went along because of fears or regional and familial loyalties. And the radicals failed in the Upper South before Sumter. It was chiefly the fact that war was already beginning that drew VA, TN, NC and AR into the rebellion and Confederacy. But ignoring the radical element among the secessionists creates a distorted picture. What many find objectionable about confederate apologists is the exaggerated contrast between the evil, power-hungry Union and the poor, dutiful, victimized Confederates. An admission that there were power-hungry and aggressive secessionists and Confederates would go some way to providing a fuller understanding of that time.