Florida voters' overwhelming approval last week of a constitutional amendment slashing their property taxes--and potentially costing schools millions of dollars in funding--illustrates the vexing trade-offs policymakers nationwide face in trying to reduce one of the most unpopular of all taxes. While lower tax bills may make homeowners happy, they threaten a precious and typically stable source of revenue for school districts, while shifting more of the financial burden to a state government already coping with budget pressures from a slowing economy. It's a drama that's playing out in a number of states this year. In New York, Governor Eliot Spitzer has called for a cap on property taxes used to pay for schools, and formed a commission to figure out the details. Georgia and Indiana already are looking at fundamental changes: reducing reliance on property taxes by raising other levies, such as the sales tax. Politically, the property tax can be hard to defend. Its growth is difficult to control, retirees on fixed incomes struggle to cope with rising bills, and high property taxes can be seen as an impediment to business and housing growth. Yet there's one big advantage: The property tax is a substantial and reliable source of revenue for local governments and school districts.