The best resource on this issue, which like most issues can be argued either way, is Robert F. Durden's ground-breaking study, The Gray and the Black: The Confederate Debate on Emancipation. Here are several reviews --
As I've mentioned many times, period newspapers make excellent historical sources. Prof. Durden uses newspapers frequently, including articles, letters and petitions found in them. A petition which impressed me was signed by nearly every officer and enlisted man of the 15th Alabama Regiment, a command I have studied in some detail. They urged Congress to advance the legislation before it. Since typical Southern boys daily worked alongside black people in the fields and towns, they readily accepted the idea of fighting together in the ranks.