A measure that would legalize slot machines at seven racetracks in Ohio was surrounded by concerns over its legality and the revenues that would flow to horsemen on Monday, when the provision was officially added to the state budget. Two groups have vowed to challenge the slot-machine measure in court if the Ohio house and senate pass the budget, as expected, late on Monday or on Tuesday. The two groups, the Ohio Roundtable and the Ohio Christian Alliance, said that the provision would violate the terms of a constitutional amendment voters passed in 1973 that provided for the lottery. The measure was added to the budget through an executive order signed by Gov. Ted Strickland authorizing the lottery to add the machines at the racetracks. The groups who oppose the measure plan to argue that voters did not contemplate slot machines when they voted to approve the lottery 36 years ago, and that any measure expanding gambling would need to go to a public vote. In addition, representatives of racing groups said that the executive order does not include any splits for purses at racetracks, leaving that up to contractual negotiations between tracks and horsemen's groups. The state has estimated that slot machines will produce nearly $1 billion in revenue for the two-year budget and help close a $3.2 billion deficit.