Times/Herald Tallahassee Bureau Attorney General Bill McCollum directed his staff on Tuesday to investigate the legality of requiring people to either buy health insurance or face a penalty a provision included in federal health care proposals. The requirement is similar to a 2006 Massachusetts law signed by then-Gov. Mitt Romney. The GOP presidential contender compared it to drivers who must buy car insurance. But McCollum said he has 'grave concerns' about what he dubbed a 'living tax.' He said it would penalize people who choose to do nothing, compared with the car insurance requirement, which is connected with the decision to own a car and drive. 'There are serious questions about whether a tax of this nature is constitutional,' he said. McCollum sent a letter to counterparts in other states, asking them to join his investigation. He also said he will join other attorneys general looking into the constitutionality of a Senate bill provision that would pay for Nebraska's share of the proposed Medicaid expansion, a deal secured by Sen. Ben Nelson, D-Neb. McCollum is the leading Republican candidate for governor in next year's election. Sen. Dan Gelber, the Miami Beach Democrat who is running to take over McCollum's job, said the attorney general should be looking for ways to provide more people with health insurance. 'I wish McCollum was as concerned about solving Florida's health care crisis as he was about stopping the solving of the health care crisis,' Gelber said in a statement. Chief Financial Officer Alex Sink, the Democrat who would face McCollum in the fall, was traveling and did not have an immediate response to McCollum's announcement. Under the Senate bill, families that don't purchase insurance could be fined the greater of $2,250 or 2 percent of their taxable income. Proposals that have cleared both the House and Senate include coverage subsidies and provisions that encourage companies to offer coverage. The two bills must be reconciled before Congress can send the health care overhaul to President Barack Obama. McCollum's inquiry comes as lawmakers in Florida and about a dozen other states are debating proposed constitutional amendments that would try to block portions of the federal health bill. Any federal legislation is likely to supersede state constitutional amendments. But supporters of the amendments, including state Sen. Carey Baker, say they want to send a message to Congress. 'We would be essentially telegraphing our intentions,' said Baker, R-Eustis. 'If there was an opt-in, we are essentially stating now that we are not going to opt in.' Information from the New York Times was used in this report. Lee Logan can be reached at llogansptimes.com or (850) 224-7263. 