A lot depends on your time management ability, but it is definitely doable. Granted I'm only at a T149

but if I can do it, most fairly intelligent people with good time management skills should be able to do it. I have a demanding full time job (County Auditor), commute about 45 minutes each way on a non-traffic day, longer on a day with traffic (which is scarce), deal with work related calls the whole drive to school, have a wife and two kids, and attend law school part-time at a minimum of 4 nights a week. I've now finished 4 semesters and one summer, and am 47/90 of the way finished. As long as I choose to keep up this pace, I should be finished after a total of 3.5 years in December 2016. I am also on a scholarship with a stip (top 25%) and despite a lot of trepidation going into it that I wouldn't be able to compete due to my time constraints, I'm in the top 10% (approximately as rankings come out again in a few weeks), should grade onto law review when rankings officially post, and have a wide enough margin now that barring me getting catastrophically ill or something equivalent, I should be able to keep myself in position to keep my scholarship, and even if I was to somehow lose it now, it would only impact my last semester as I've already punched my ticket for the next 2 semesters.
Along the way the last couple of years, my marriage has actually improved, as I find that the limited time I spend with my wife now I'm actually paying attention and being grateful for it and actually LISTEN, rather than taking her for granted. We are actually much closer now than when I started this two years ago. Two things I miss are being able to coach my daughter at sports and performing with my son in theatre, but there WILL be some sacrifices you have to make. I still take time to be a good dad for them and to spend time with them, and they spend so much time in extracurricular activities, that they don't miss me as much. My 1L year, I learned what I had to do in order to be successful in law school, and where I could cut corners. This past year, I had so much more "free" time due to doing law school efficiently, work smarter, not harder. I even volunteer as a TA and teach other new law students "Academic Support" sessions each week to teach them how to succeed in law school. I did that this past year and thoroughly enjoyed it.
Now though, when I do have free time, I feel guilty for not doing something productive
Find something that motivates you intrinsically, and use it to push yourself. I was a POOR student at my undergrad (Notre Dame) over 20 years ago, probably had one of the worst undergrad GPA's on this entire board, so I had something to prove to myself and I wanted to show my kids what dedication and work could do for one's grades.
Although law school is competitive, find a support system there that helps you thrive. I've developed several close friends over shared life experiences at law school, including professors, and we help each other out by doing things like sharing in bringing or providing dinner at class, sharing notes, outlines, class recordings, and in just being there for each other when we need someone to detox with.
Of course I don't know you personally, and you probably go to a school with a heckuva better reputation than mine, but don't let anyone make you believe that you can't do it, if you really want to.
Good luck to you, and I hope it works out for you,
Leprechaun