Please do not take the rankings to seriously remember it is nothing more than an unregulated for profit magazine offering an opinion. Additionally U.S. News ranks more than law schools and currently New Mexico is the best place to live citation here. http://money.usnews.com/money/personal-finance/slideshows/best-places-to-live
Are you going to move to New Mexico because U.S. News said it is the #1 place to live? I hope you would not make the life altering decision to move to New Mexico simply because U.S. News said it was the #1 place to live. On the same vein do not make the life altering decision of transferring law schools because U.S. News has changed the ranking. Also realize the U.S. News formula makes little to no sense for that reason schools rankings change drastically year by year.
You can look at this table to see how often schools have changed over the past four years. http://www.top-law-schools.com/rankings.html
if you transfer it is very possible the school you are attending now will rise above the school you transfer to. Schools can jump 20 to 30 spots any given year.
On top of that I can tell you very few firms care about the U.S. News Rankings outside of the "Top" law schools. If you were transferring to Harvard or Yale it could open more doors, but if your transfering from say Florida International to Stetson or Gonzaga to Seattle nobody cares about the difference between the 92nd and 112th best school.
If you are content at your current school stay there. Remember legal education at every school is essentially identical I do not know what law school you attended, but I imagine your first year consisted of Torts, Civil Procedure and Property. In Torts you read Palsgraff for Proximate Cause and Pennoyer v. Neff for Notice etc. In the end you will learn the exact same things whether your transfer or not and when you graduate you will then take BarBri or Kaplan for your State's Bar exam and be in a room with law students from around the Country learning the same thing. You will then take the Bar Exam, which will be very stressful and if you pass you will have a license to practice law. Once you are a licensed lawyer what you with it will matter much more than the arbitrary U.S. News Ranking of the school you attended.
I cannot tell how many law students place so much emphasis on these rankings, but frankly they are B.S. Obviously Harvard, Yale Stanford etc will open doors and you didn't need U.S. News to tell you those are elite institutions, but frankly outside of the "top" law schools I have no idea what the various rankings are and I am an attorney that reviews resumes.
Also you should be very concerned with the Debt you incur and eating credits based on a magazine. Stay where you are unless you have legitimate reason to transfer such as family emergency or something, but if you had an interview with my firm and told me you decided to pay an extra 25,000 dollars and took an extra semester of law school based and left all the friends and connections you made at your current school based on a magazine I would question your judgment.
All I can say is use common sense and do not make life altering decisions based on opinions published by a for-profit and unregulated magazine.