Cloverleaf Enterprises, which owns Rosecroft Raceway, and the American Federation of State, County and Municipal Employees, each plan to spend at least $10,000 on efforts to pass the referendum on slot-machine gambling, which goes before voters Tuesday, according to filings made with the Maryland State Board of Elections. Rosecroft would not be eligible to bid on a slots license if the proposal is approved, but Cloverleaf Chairman Kelley Rogers said the track would benefit from slots proceeds set aside to enhance horse-racing purses. The track suspended live racing this summer because of financial difficulties. Cloverleaf plans to spend more than $40,000 on phone banks to ask voters for their support. AFSCME has endorsed the referendum as a way to help solve the state's budget shortfalls.