A year after Colorado became the first state to allow recreational marijuana sales, millions of tax dollars are rolling in, dedicated to funding school construction, marijuana education campaigns and armies of marijuana inspectors and regulators. But a legal snarl may force the state to hand that money back to marijuana consumers, growers and the public — and lawmakers do not want to.

The problem is a strict anti-spending provision in the state Constitution that touches every corner of public life, like school funding, state health care, local libraries and road repairs.

Technical tripwires in that voter-approved provision, known as the Taxpayer's Bill of Rights, may require Colorado to refund nearly $60 million in marijuana taxes because the state's overall revenue estimates ended up being too low when the marijuana tax question was put to voters. Lawmakers are scrambling to figure out a way to keep that money, and they are hoping Colorado voters — usually stingy when it comes to taxes and spending — will let them. In rare bipartisan agreement on taxes, legislators are piecing together a bill that would seek voters' permission to hold on to the marijuana money.