DENVER (AP) — Colorado's marijuana experiment was designed to raise revenue for the state and its schools, but a state law may put some of the tax money directly into residents' pockets, causing quite a headache for lawmakers. Legal weed has collided with the tax limitation movement because a 1992 voter-approved constitutional amendment called the Taxpayers' Bill of Rights requires all new taxes to go before voters. Republicans and Democrats say there's no good reason to put pot taxes back into people's pockets, and state officials are scrambling to figure out how to avoid doling out the money. [...] they also tend to say that marijuana should pay for itself — that general taxes shouldn't pay for things like increased drug education and better training for police officers to identify stoned drivers. After legalizing marijuana in 2012, Colorado voters returned to the polls the following year and approved a 15 percent excise tax on pot for the schools and an additional 10 percent sales tax for lawmakers to spend. Previous refunds have generally been paid through income tax returns, but Colorado also has reduced motor vehicle fees or even reduced sales taxes on trucks.