The Center for Education Reform examined charter school statutes for each state and ranked them as A, B, C, D, and F which I have coded as +++ etc. The ranking is primarily on how much autonomy schools have, parity of funding, number of schools allowed, etc. Each state is followed by the number of charter schools and the ranking. You will notice 10 states do not have charter statutes and 20 states have weak statutes. That leaves 21 states (the ones with a +++ or ++ sign) with strong or reasonably strong laws.
CHARTER SCHOOLS in U.S.2006-07
40 states + DC 3977 schools, about 1,150,000 students
A +++ B++ C D- F–
Alaska 26-
Arizona 466 +++
Arkansas 17 -
California 625 ++
Colorado 133 ++
Connicticut17
Deleware19 +++
District of Columbia 70 +++
Florida 391 ++
Georgia 55
Hawaii 27
Idaho 26
Illinois 53
Indiana 37++
Iowa 7–
Kansas 27 -
Louisiana 54
Maryland 25-
Massachusetts 59 +++
Michigan 241+++
Minnesota 137 +++
Mississippi1 –
Missouri 25 ++
Nevada 22
New Hampshire 9
New Jersey 55 ++
New Mexico 64 ++
New York 98 ++
North Carolina 100 ++
Ohio 293 ++
Oklahoma15
Oregon 67 ++
Pennsylvania 122 ++
Rhode Island 11 -
South Carolina 34
Tennessee 12
Texas 269 ++
Utah 54
Virginia 4 -
Wisconsin 207 ++
Wyoming 3