Just how close is the same-sex marriage referendum?

OVER THE WEEKEND, the results of four separate opinion polls on voter intentions in the same-sex marriage referendum were published.

All of them showed a broad trend: the Yes side continues to lead but the margin has narrowed and the No side is catching up.

Let’s take a quick look at the main figures…

An Ipsos MRBI poll in the Irish Times found:

Yes 58% (down 6)

No side 25% (up two).

Don’t know 17% (up 5)

A Red C poll in the Sunday Business Post found:

Yes 69% (down 3),

No 25% (up 5)  

Don’t know 6% (down 2)

A Millward Brown poll in the Sunday Independent found:

Yes 53% (down 13)

No 24% (up 3)

Don’t know 23% (up 10)

A Behaviour and Attitudes poll in the Sunday Times found:

Yes 63% (down 10)

No 26% (up 4)

Don’t know (up 5)

Across all four polls, when the Don’t Knows are excluded, there is still strong support for a Yes vote of between 69 and 71 per cent. But it has fallen by between 4 and 7 percentage points.

Support for a No vote has risen across all four polls by between 4 and 7 percentage points and accounts for around 30 per cent of voters.

This indicates that support for Yes is strong, but it is the ‘don’t knows’ that campaigners on both sides will be watching. The Millward Brown polls indicate that nearly a quarter of voters (23%) are undecided. The Red C Poll says that just 6% are on the fence and that’s down two points from the previous poll last month.

Whatever the actual figure is pollsters believe that those who fall into this ‘don’t know’ category are more likely to vote No. But, even if all of them did, that still indicates, on current numbers, that the referendum will pass.

But then there is the great unknown. The so-called ‘shy voters’.

This phenomenon emerged quite spectacularly in the recent UK elections where the ‘shy Tories’ came out in force to elect David Cameron and his Conservative government with a small majority. This was despite all the pre-election opinion polls indicating a hung parliament was a certainty.

Shy Tories kept this man in 10 Downing Street Scott Heppell Scott Heppell

In 2011, there was an expectation that shy Fianna Fáil voters might save the party from near wipe out and indeed Micheál Martin’s beleaguered forces did slightly better than most opinion polls suggested, taking just over 17 per cent of the vote when they had been expected to get 16 per cent.

But general elections are somewhat different to referendums. After all, the polls prior to the last Scottish independence referendum got it largely right. Then again, Ireland can be a different beast. Remember when all polls indicated that people were in favour of abolishing the Seanad? Yet, the upper house lives on.

On a particularly sensitive social issue such as same-sex marriage, there is a belief among many campaigners on both sides – and indeed the pollsters – that there are a lot of people out there who will use the secrecy of the voting booth to cast a No vote. But they wouldn’t dare tell a polling company, even anonymously, that they intend to do so.

There is no way of accurately calculating how many ‘shy No voters’ there are. Red C attempted to figure it out by asking the people they polled last week what they believe the outcome of the referendum will be – as distinct from which way they will vote. The result was 61 per cent of likely voters saying they think the referendum will be passed, while 38 said they think it will be defeated.

This tell us the race is closer than the polls might indicate, but that Yes remains on course to win. Still, it doesn’t give us an accurate read on exactly how many ‘shy No voters’ there are out there, and everyone is pretty sure they exist.

Nuns voting in the 1995 divorce referendum EMPICS Sports Photo Agency EMPICS Sports Photo Agency

That the Yes side’s lead has narrowed will come as no surprise to campaigners on either side of the debate. This has been a trend in many Irish referendums of the past where a seemingly unassailable Yes vote is whittled down as the campaign wears on and the debate rages on the airwaves, in the papers, down the pub and, in recent years, online.

Same-sex marriage has generated the sort of referendum debate across Irish society that we arguably haven’t had since the 1995 divorce referendum. On that occasion we saw a significant support for a Yes vote narrow as the campaign wore on to the point where the referendum passed by just over 9,000 votes.

In May of 1995, six months before the actual vote, more than 70 per cent of those asked said they would be voting in favour of the amendment.

But by November of that same year, all polls showed that the Yes campaign’s lead had narrowed considerably.  Six days before the vote, an Irish Times poll found 51.7 per cent in favour of the amendment with 48.3 per cent against.

One thing we can say for certain this time around is that four days before this referendum, there are no polls which indicate it is as close as it was in 1995.

One other factor to consider is the surge in the number of people registering to vote in recent weeks. Some 65,000 people have added their name to supplementary register ahead of the referendum. Yes Equality believes this will boost its chances considerably.

The question is whether or not these newly-registered voters turn out on the day and will their impact for the Yes side be greater than the impact of the ‘known unknown’ that is the ‘shy No voter’?

These are questions that will only be answered definitively on Friday when the people have their say. What we can say with certainty now is that the Yes side has a clear lead. It is not unassailable, but all indications are that this referendum will pass.

Read: How did the polls change in the run up to other recent referendums?

Read: Do you have any questions ahead of the referendums next week?