From the introduction to an analysis by the Tax Foundation:
The state of Colorado is under assault. Opponents of Colorado’s Taxpayer Bill of Rights (TABOR) are waging a well coordinated but misleading attack on Colorado’s reputation. This attack takes the form of a number of rankings and statistics that purport to show that the Taxpayer Bill of Rights has decimated Colorado. These rankings and statistics are based on the assumption that if Colorado ranks poorly on things like the adequacy of prenatal care and education spending, then Colorado is failing to adequately care for and educate its citizens, and that the Taxpayer Bill of Rights must be to blame. A closer look at the attacks shows that they fail to prove that the amount a state spends on health care and education determines quality, and they also fail to tell the whole truth about the rankings and statistics of the state of Colorado.
The full article is here: An Analysis of Misleading Attacks on Colorado’s Taxpayer Bill of Rights