Big reason is that my employer will pay almost 50% of my tuition and while working I will be able to pay my mortgage and my tuition too. I am just looking for improvement in my career, something better.
Personally, I wouldn't even think twice. If your employer will pay half your tuition and you can still earn a decent income, do it. I firmly believe that less debt = more opportunities. PT students CAN get externships, internships, clerkships, and jobs. I've met so many people who are now working at respectable firms that went part time. Yes, you have to be creative and excel at time management and organization and get over the fact that you have NO flexibility in your schedule. But it's doable. The biggest disadvantage is you lose out on some of the programs that are only offered during the day - but, for me, that's not as important as minimizing debt. You have to be diligent about seeking out opportunities that will help you, but it's doable. Talk to other PTers and see how they did it. It reflects well on your character when you can manage law school and work, especially if you keep your grades up. And the other students in your program are going through the same thing so you won't feel like you're going completely crazy all by yourself.
I also went to grad school while working, and law school is totally different. You cannot skim (or skip) the reading, show up, and expect to do well. The material isn't hard - you just have to master it, which takes time.