Many believe a weakening economy that exacerbated the state's fiscal problems helped break the logjam in Annapolis - and will bolster support for the referendum.
"The bottom line is that the economy is driving this," said Laurence Levitan, a former state senator and a lobbyist who has represented gambling interests. Compared with other revenue raisers, such as tax increases, "this is an acceptable solution," he said.
O'Malley and Busch have predicted the issue will finally be put to rest should voters say "no" to slots.
Miller, however, declined to say whether he would continue to champion slots as he has for years if the referendum fails. "I'm fairly certain it's going to pass," he said, "and I'll address the election results afterward."
Should voters approve slots, the plan still faces roadblocks, and could be altered in the future.
Some observers predict a zoning fight in Anne Arundel County, though County Executive John R. Leopold, a Republican who opposes the plan, said he hasn't decided whether he would try to block rezoning to authorize expanded gambling if the measure passes. Others say a lawsuit might be filed to block slots at Laurel Park if it wins a license to operate them.
A city-owned parcel that would accommodate a gambling casino in South Baltimore also would have to be rezoned, but Mayor Sheila Dixon and City Council President Stephanie Rawlings-Blake both strongly support the proposal, so legislative hurdles are less likely there.
The economy could also provide obstacles. A tight credit market, a gambling industry hampered by slowing consumer spending, and a relatively high tax rate imposed on gambling operators all combine to lend uncertainty to whether, and how many, casino operators will bid on the five licenses.
Lawmakers could change the tax rate on their own.
But any changes to the locations or number of machines would have to go back before voters in the form of another constitutional amendment.
After months of campaigning - and years of deliberating slots proposals - the referendum vote does represent a finish line of sorts. "It will be a relief to everybody," O'Malley said. "I'm looking forward to Tuesday."
gambling in maryland
1743 - Horse race wagering first regulated in Maryland.
1912 - Pari-mutuel betting introduced.
1937 - Slot machines first authorized for use in Maryland.
1968 - Legislative ban on slots, common in Southern Maryland, takes effect.
1972 - State lottery established through constitutional amendment.
1990 - Slot machines legalized in West Virginia.
1995 - Slots come to Delaware.
1995 - Tydings Commission recommends prohibition on slot machines and other forms of gambling expansion.
1996 - Gov. Parris N. Glendening vows no slots in Maryland.
2003 - Gov. Robert L. Ehrlich Jr. launches a lobbying effort to promote slots legislation but loses first of several attempts to pass gambling bills
2006 - Slots come to Pennsylvania.
November 2007 - Gov. Martin O'Malley and legislature agree to let voters decide slots question.
November 2008 - Maryland votes on slots.
