Whenever marriage equality has gone before the public in a referendum, it has lost. As a result, 31 states ban legal recognition of same-sex couples. Four states — Maine, Maryland, Minnesota and Washington — will put the question to voters this November. So it’s understandable that proponents of same-sex marriage would worry about anything that would stand in the way of victory — a first victory — at the ballot box.

Last week, I told you about the disquiet in the gay community about the efforts by Maryland Gov. Martin O’Malley (D) to arrange a special session of the legislature to approve a bill legalizing a sixth casino. This measure would require the concurrence of Marylanders at the ballot box in November. The battle on both sides will be intense, with millions being spent by casino operators to kill or save the new casino project. And the big fear is that there will be “potential for collateral damage,” as Chrys Kefalas, former legal counsel to former governor Robert L. Ehrlich Jr. (R) told me last Wednesday, as more conservative voters swarm the polls to have their say.

But other proponents of marriage equality aren’t nearly as pessimistic, and they have the numbers to back up their rosier view.

“The momentum on this issue is on our side,” said Rick Abbruzzese, a spokesman for O’Malley. “The numbers are going in the right direction. President Obama’s endorsement [of marriage equality] has helped, and we’ll have an aggressive grass-roots campaign.” He added, “Marylanders have always voted to expand opportunity.”

“The gaming initiative on the ballot won’t have too much of an effect,” Marylanders for Marriage Equality campaign manager Josh Levin told me. “Just about every voter who is going to come out is going to come out.”

A Public Policy Polling (PPP) survey commissioned by Levin’s group put support for the marriage referendum at an astounding 57 percent. But even the most enthusiastic backers of that effort take the poll result with a grain of salt.

A survey of 700 voters, representing the likely 2012 Maryland electorate, who were interviewed by telephone June 28 through July 7 (interviewing was suspended during the electrical outage). The study uses a registration-based sample and has a margin of error +/- 3.7% at 95% level of confidence. The margin of error is higher for subgroups. (The Mellman Group)

The gaming amendment is widely popular, with voters favoring it by a 57%-31% margin. Support spans gender, ethnic, geographic, and age boundaries, with majorities of men, women, whites, African Americans, Washington market residents, Baltimore market residents, older voters, and younger voters all in favor. Additionally, strong support (42%) nearly doubles strong opposition (24%).  

Pollsters also asked the “700 voters representing the likely 2012 Maryland electorate” how they would vote on a marriage-equality referendum. They found that supporters of gaming are also more likely to favor the marriage referendum.

Voters who plan to vote yes on the gaming amendment support the marriage referendum by a 63%-29% margin (a net 34 points in favor), while gaming amendment opponents oppose the marriage referendum by a 34%-54% margin (a net 20 points opposed).

“Thus,” the memo concludes, “fears that the gaming amendment will suppress support for the marriage referendum are unwarranted.”

Another factor in all this is how the presidential election would impact turnout on either ballot measure. “[I]t is hard to believe that a referendum, no matter how controversial, would by itself drive up turnout among ‘reluctant’ voters in a PRESIDENTIAL year, which is typically the highest turnout election,” another Maryland-based pollster with extensive experience in the state told me in an e-mail.  He used data from the 2004 and 2008 presidential elections to show how the fears among gays about the impact of the gaming amendment are pretty much unfounded.

In the 2008 election, Maryland voters turned out for a historic presidential ballot and to have a say on whether to allow casino-style gambling in the state (Question 2).  

Total votes cast in presidential race: 2,631,434

Total votes cast for Question 2: 2,525,424

The pollster pointed out that turnout in 2008 was higher than the 2,384,195 voters who cast ballots in 2004. “[T]hat’s because between 2004 and 2008 roughly 800,000 more Maryland residents registered to vote (growing population PLUS the Obama campaign’s registration efforts),” he wrote, adding that 76 percent of eligible voters turned out in 2008 vs. 90 percent who did so in 2004.

“As you remember, Question 2 was a very visible issue because it was the culmination of years of debate in Annapolis, and this was the FIRST time that MD voters would get to decide.  BOTH sides ran high-profile, energized efforts,” the pollster noted. “IF ANY issue was going to motivate higher turnout, Question 2 would be the issue.  Yet (A) FEWER people voted in Question 2 than the presidential, and (B) remember the total % turnout in 2008 was LOWER than 2004.”

That’s pretty compelling data that should allay some fears about the impact of a gambling amendment this November. We should be mindful that such an amendment may not even come before the voters. O’Malley had said that he would release a proposed bill last Friday.  The Baltimore Sun reports today that the governor has yet to submit the bill and that “there are no obvious signs of significant progress in reaching a deal the House, Senate and O’Malley administration can all agree on.”

If there’s no special session, the gambling worry will fade away. But don’t think for a moment that means the pro-marriage equality folks should rest on their laurels. “I think it’s close,” said Levin of Marylanders for Marriage Equality. “We all know this is going to be closely fought until Election Day, and I don’t think either side will take it for granted.”