I believe that there would be at least eventually.
Most Confederacy scenarios are North South Focused, Ignoring the East West divide, that is very strong. Once the war is over, the West will slowly realize its advantage lies more with the North and with the south. Consider the following:
1. Poor rail system in the South, which would be no better after the war. This will mean travel into the west will be hampered, and will probably result in a breakdown of th efeeling of nationhood.
2. Western sales of beef to supply northern slaughterhouses. This will result in cross border traffic as they pass South to North.
3. Strong US linked economies growing on the West Coast. The Western portions of the CSA will want their peace.
4. Old plantation system politics of the 'deep south'. If you think our south had a bad record in the last century, think what would happen in TTL.
At the very least, Texas would eventually go, particularly as the non-slave owning portions of its economy grow. It already has a history of independence, so the temptation would be very great.