Don't worry about the rankings they are literally a joke see this articles from LSAC. http://www.lsac.org/JD/Choose/deans-speak-out-rankings.asp
. Realize U.S. News system is not approved by the ABA or AALS or any organization it is a for-profit magazines subjective opinion and this is the formula.
40% of the ranking is based on lawyers & academics marking a scantron from 1-5. So some judge in Florida marks a 2 for Phoenix and has never been to Phoenix law school or knows anyone from there. This is simply retarded there is no other way to put it unless you are rating the top 20 or so schools. There is no way for a judge in Spokane to determine whether Washburn is better than Florida International. This makes up 40% of the ranking.
20% is based on job placement, which would be a good criteria except for the fact that "placement" could be working at McDonald's or making 200k a year. This website lawschooltransparency.com lists actual salaries so it presents some information, but by looking at this site you can see almost all law student salaries are unaccounted for.
Bar Passage, which I think it is important makes up 3%, but U.S. News doesn't seem to think passing the bar is important. LSAT score which is something that makes sense to measure law schools by makes up only 12.5% GPA makes up 10%, which is a decent measure, but students can manipulate GPA getting a 4.0 in religious studies or theory of basketball is more impressive to this magazine than a 3.2 in molecular biology and I think understanding molecular biology is more impressive than theory of basketball or basket weaving or whatever b.s. major a student could use to manipulate the magazine. I did this in undergrad and got a ton of scholarship money for law school.
Faculty resources make up 15% of the ranking which makes sense. This formula is all see on page 5 of this article. http://www.lsac.org/LsacResources/Research/GR/GR-07-02.pdf
The methodology is flawed and as a result of this outside of the "top" schools they jump 10-20 spots in any given year and the magazine has basically given up trying to be credible by placing every school in a tie and my personal favorite is the current 11 way tie for 84th place. You can see the ties here. http://grad-schools.usnews.rankingsandreviews.com/best-graduate-schools/top-law-schools/law-rankings/page+4
Needles to say the rankings are irrelevant when considering non-elite schools and for your purposes don't worry about them. Obviously, Harvard is a damn good law school and Phoenix is not on par with it and I assume you know that. However, Phoenix is an ABA school and at any law school you will learn the law. You will read supreme court decisions, statutes, learn how to use Westlaw & Lexis, and so on. The law is the law in your first year to will take torts, property, contracts, criminal law, con law, and civil procedure. You should also consider the location if you have no desire to live in Phoenix then going to law school out there might not be the best idea. Phoenix probably won't have much reach outside of Phoenix although an ABA approved law school will allow you to be a lawyer in any state, but Phoenix is not going to wow employers and you going to bear the burden of starting your legal career.
Also remember any type of education is a LONG-TERM investment. If you go to law school you will have the ability to practice law the rest of your life and the money part will work itself out. So the real question is whether you want to be a lawyer or not if you have a burning desire to be a lawyer then go to law school. If your doing it for the sake of doing it then 3 years of your life and 180k won't be a good idea.
Sorry for the long rant, but I myself was overly worried about the rankings etc when choosing a law school, but it really comes down to common sense. Law school teachers you the law and odds are you are going to be end up working where you go to law school. Also realize when going to a non-elite school nothing will be handed to you, but you can definitely succeed. Hopefully something in there was useful and good luck to you.