Wow. You're kind of me...
First, a few random points. If you think you want to pursue an engineering major, for whatever reason, go for it, regardless of what you want to do later. I know multiple students doing this (they're actually all heading to law school...an engineering background is imperative in certain branches of law). But don't study something that doesn't interest you, whether that's engineering or anything else (and the good news is that if you want to go to law school, you can really major in anything you want). One consideration is that if you do want to go to law school, your GPA will be VERY important and engineering is not an ideal way to keep it high. If you love engineering and think law school is a vague possibility, then I'd never recommend basing your undergrad major on this type of consideration, but that doesn't really sound like the case...so anyway, just pointing it out.
So, when I applied to schools, I had no idea whether I wanted to do engineering or liberal arts (at the time, I thought English). I ran into the trouble you might have, which is that many schools forced applicants into the College of Engineering or the College of Letters or whatever else, and I really just didn't know at that point. I ended up applying to non-engineering schools when forced to choose, figuring that if I changed my mind, it'd be easier to do a math major from there than an English major from the college of engineering (and math, much more than science, was what drew me to engineering).
I ended up choosing one of the Claremont Colleges (not "the engineering one"), knowing that whichever direction I ended up going, I'd have great resources available to me (If I'd wanted to do engineering, I think I would have had to do a 3-2 program, but I wouldn't have had to apply straight into it, as I recall). I ended up pursuing a liberal arts major (Philosophy) and a math minor (partially because of my own interest, partially because of my dad's), so everything worked out.
The POINT to all this is: don't stress too much about this issue. Engineering can be a great (and in some cases necessary) background for law school, but it could also drag your application down. As an engineer, you'd likely be very employable right out of undergrad, while law school will run you $100K+ in grad school funds. If you do declare one major but change your mind part way through, I think you'd have an easier time making up humanities or liberal arts courses than you would making up engineering courses (which tend to build more heavily on one another, making sequence and timing more important than in many other fields).You could debate this issue into the ground if you really needed to, but I would just suggest applying to a wide variety of programs, a few flexible programs, and just seeing where things take you. As a general rule, liberal arts colleges will allow you more flexibility with less bureaucracy than larger universities, although you'll be a little more limited in your choices (engineering is offered less often at LACs).
Really, I just wanted to let you know that I empathize with how confusing the situation seems, but let you know that it'll work out and it's not that weird of a situation
