Contact your schools directly and ask if this practice is frowned upon. Perhaps they only glance at personal statements and the particular schools you are applying to rely almost exclusively on your undergraduate grade point average and your Law School Admission Test (LSAT) scores to make their decision. In these cases, using the same statement may be acceptable.
Update your list of schools, if necessary. If the schools you contacted suggested they seriously consider the personal statement, you may want to add a few new schools. Because while it is unlikely that your personal statement will be remembered by the admissions committee members, if it was very memorable, it may well be. In this case, using the same personal statement may hurt your application by showing a lack of effort on your part. Adding a few schools for whom the personal statement is new will mitigate this potential problem.
Work on the parts of the application you can change. This may include polishing your resume, getting new letters of reference, or retaking the LSAT and aiming for a higher score. Although the personal statement is important, it is not the only part factored into an admissions decision.
Revise your personal statement. Even if your statement is essentially the same, tweaking it here and there may make it more substantial. Ask a mentor or friend to look over the personal statement and address the weakest parts; then, revise your statement accordingly. A new opening or ending may be all you need to transform the statement from good to great.
Add briefly to the personal statement. For example, it may require an update if there is an achievement within that past year you would like to mention. Or, adding a final paragraph where you briefly discuss your specific reasons for wanting to attend a particular school can show diligence and dedication.