At a March 20 statehouse rally in Boston, hundreds of local horsemen, track employees, city mayors, and labor leaders pressed lawmakers for action on a proposal that would add 2,000 slot machines at each of the state's four pari-mutuel facilities.Sensing their best chance for alternative gaming in more than a decade, supporters called on legislators to back the plan, arguing that all Massachusetts citizens stand to benefit from the estimated 4,000 jobs and $500 million in revenue the slots are expected to generate each year."We can't afford any more delays," Mayor Thomas Ambrosino of Revere, whose city has a Greyhound track and the backstretch at Suffolk Downs, told the rally. "This industry is on its last legs."A slots bill gained a wide margin of approval in the Massachusetts Senate in October (officials canceled a day of live racing at Suffolk and staged a similar demonstration), and the House of Representative announced late in the day March 21 it would take final action on its long-stalled companion version of the bill April 5."This date certainly is great news," said local trainer Jeff Hooper, executive director of the New England Horsemen's Benevolent and Protective Association. Hooper said the industry stands to lose roughly 6,000 jobs if the tracks close their doors, widely expected to happen within two years without the machines."We've got a very good chance of (House) passage," Hooper said, "and the legislature did the right thing by considering the slots before taking up the full simulcast law."In December, the legislature gave the industry a 90-day extension of the existing simulcast law that was to expire Dec. 31. Hooper said the legislature will likely pass a similar 20-to-30-day extension before taking up the simulcast bill April 10.The bill's supporters claim a majority of support in the 157-member House, though mobilized anti-gaming interests, a non-committal Speaker of the House Salvatore DiMaisi, and Gov. Mitt Romney, who threatened to veto any expanded gambling measures, remain significant hurdles.A Boston Globe poll published March 13 showed 53% of voters surveyed favor legalization of slot machines. The poll also concluded nearly one-third of respondents traveled outside the state to gamble, spending an estimated $1 billion at Foxwoods and Mohegan Sun casinos in Connecticut, and at Lincoln Park, a Greyhound racino in Rhode Island.Opponents argue the tracks are getting a windfall at taxpayer expense with the proposed $25-million licensing fees. They contend the state should receive upwards of $85 million per track based a $285-per-day, per-machine model used by the Maryland legislature in its deliberations on a similar casino bill, according to a recent television broadcast on the New England Cable News Network.The four tracks in Massachusetts are Suffolk Downs (Thoroughbred), Plainridge Racecourse (Standardbred), and Raynham-Taunton and Wonderland (both Greyhound).