This is our experience in Oregon. The courts don't care. My husband (NCP) made the "choice" to go to school and become "underemployed." There are supposedly exceptions; although we have tried to prove that our situation falls under more than one of them, CSE just doesn't listen. Here is a little more of what we have been told.
If my husband had been making a lower-than-average wage prior to starting school, it would be an acceptable reason to go to college, to "improve" his and his family's circumstances.
CS may be lowered for school if there is a health or other reason--certified by a physician--that the NCP cannot work full-time or continue in his/her previous career. My husband was injured on the job (construction), temporarily paralyzed, on full worker's comp for 8 months until he was declared "medically stationary." CSE still didn't accept this as a reason to go back to school.
We also tried other arguments as well, not all related to school attendance. CS in this state is just a joke--I could go on and on. Not only did CSE impute my husband's potential income, they also added in his financial aid to calculate the amount. We plan on doing something about this sometime--more than one attorney has told us CSE is off-base. But until we can afford the attorney, we just pay what we can and let CS arrears accrue (and plan on our huge tax return going to CS to get us caught up.)
All that said, I would still encourage your husband to GO TO SCHOOL! There are tons of resources! Try fastweb.com. It is a free service that sends you notices of scholarships, grants, etc. that you may be qualified for. My husband found a scholarship that pays 90% of his costs.
It is not an easy road, but it is worth it!! My husband went straight into construction after high school. Started college just after his accident, and will finish his BS in just 2 1/2 years. He is planning on attending law school this fall. I am so proud of him. And his children, especially my SDs, are proud that their dad is in school. We have struggled financially--especially since our recent decision that I stay home with our children--but we have managed. I am very proud of the fact that we have reduced our monthly bills by more than half what they were three years ago.
Child support is a PAIN! I don't begrudge my SDs having financial support from their father, but they should not receive more than us. If they lived with him, they would be living on less income and doing fine. Anyway.... like I said, don't let CS stop you from pursuing an education, bettering your life and your children lives.