Following the decommissioning of some weapons by the IRA, Sinn FΘin's potential political role in the Republic has become a matter of considerable interest.
All four of the national MRBI polls between September last year and May this year have credited that party with the support of at least 5 per cent of the electorate, the average for the four being just over 5.5 per cent. That proportion is one-quarter higher than the support credited to the Green Party in these polls, and is three-fifths more than that of the Progressive Democrats.
This figure may, however, underestimate electoral support for Sinn FΘin. For, in the Republic as in Northern Ireland, some people interviewed by pollsters have been reluctant to admit an intention to vote for Sinn FΘin. Thus in the pre-Election polls in 1997 only 1.4 per cent of those interviewed who disclosed an intention to vote named Sinn FΘin as the party of their choice. But in fact, when allowance is made for the fact that the party contested only 12 constituencies in that election, its support in 1997 was equivalent to 4.25 per cent at national level - three times that suggested by the polls.
No doubt, since the Belfast Agreement this non-disclosure factor has diminished, but it would be surprising if it has disappeared altogether, so that with declared support averaging 5.5 per cent their actual support at the time these polls were taken may well have been at least 6.5 per cent.
It is worth noting that the MRBI constituency polls for Kerry North and Dublin South West suggest an increase of about 50 per cent since 1997 in support for the Sinn FΘin candidates in these constituencies, and that increase would also seem to point towards a potential voting strength of about 6.5 per cent at national level.
Of course, this could rise further following the initiation of decommissioning, especially if this process is continued and brought to completion before the general election.
How might such a level of support translate into seats at the election? For several reasons this is very difficult to assess.
First of all the law of averages which applies to parties with large shares of the vote does not apply to those with a small share. Thus while the Progressive Democrats had precisely the same share of the vote in 1997 as they had had in 1992 ( 4.68 per cent), this gave them 10 seats - but only four at the last election.
Moreover, Sinn FΘin's support is very localised: apart from the special case of North Kerry it is highly concentrated in Border areas and in some deprived working-class areas of Dublin.
Now, even if, as seems likely, the Sinn FΘin vote in the next election is at least 50 per cent higher than last time, with one exception it is hard to see the party having a prospect of winning seats outside seven constituencies where in 1997 it received over 6 per cent of the vote. (The exception is Dublin North West, which for some reason Sinn FΘin did not contest in 1997 but where its share of the vote in 1992 suggests that it may have potentially significant support.)
However, with a significantly increased vote Sinn FΘin might conceivably win a second seat in Cavan Monaghan.
Thus the outside limit of Sinn FΘin success in the next election would appear to be eight seats, and, although one certainly cannot rule out the kind of fluke results that the Progressive Democrats experienced in the last two general elections, it seems unlikely that Sinn FΘin will win more than four or five of these.
In other words, because of the localised character of its support, which means that in most areas its thinly spread vote is too small to yield any seats, its share of Dβil seats seems likely to be only about half of its vote share.
There are, moreover, two other reasons why Sinn FΘin's capacity to win seats may be more limited than the size of its likely vote suggests.
First of all, it attracts few preference votes from other candidates who are eliminated while the Sinn FΘin candidate is still in play.
The other factor militating against Sinn FΘin is the highly skewed profile of its support, as demonstrated by recent national opinion polls.
Sinn FΘin has the declared support of almost 8 per cent of men - but of only 3.5 per cent of women, most of whom are more queasy than men about anything associated with violence. But more important from the point of view of turnout is the fact that the party's support is also strongly correlated with age, rising from 2 per cent among those over 65 to about 11 per cent for the 18-24 age group. And its support is also twice as great among working-class voters as among the middle class and farmers.
But the young working-class voters are precisely the ones least inclined to turn out on election day.
And that raises an issue that our established political parties need to address: the danger of a significant level of impersonation being attempted, especially in urban areas.