The graph shows where voters lie. It should be read a bit like you would an OS map, the darker the shade the more voters are in that position. We see Fianna Fail is clearly closest to where the main bulk of voters are. We can also see that on the left is a pretty crowded field, with Sinn Fein the only significant player.

When Donald Trump announced he was withdrawing the US from the Paris Agreement on climate action, he said he represented voters in Pittsburgh and not Paris.

One of the lessons of 2016 politics was that there is a group of voters unrepresented by mainstream parties. The poor whites in the Rust Belt states and white-van man in the east of England were not represented by left-leaning parties obsessed with esoteric issues like non-gender toilets.

These voters didn't listen to their supposed political leaders on Brexit, and surprised most of us when they voted for Trump.

Not leaving voters behind is a key part of a party leader's job. Move too quickly and you'll find yourself isolated and without support.

An early act of Leo Varadkar as the new leader of Fine Gael was to make sure he was bringing everyone along. As a young, urban politician he could be expected to hold the liberal views that most young urban people hold. His failure to win a majority of the members meant it made sense to reassure traditional Fine Gael voters by saying: "Fine Gael should be a warm house for social conservatives."

He wasn't saying that he wanted Fine Gael to become a social conservative party. What he's really trying to do is depoliticise the issue.

Parties such as Fianna Fail and Fine Gael attempt to take some issues out of electoral politics. They are broad-based parties that encompass many different views. Fine Gael won't win votes by giving focus to abortion as an electoral issue, so they offer free votes to TDs - and send it off to the Citizens' Assembly in an attempt to establish consensus.

Parties want to campaign on issues that don't split their support. If it's plausible, they focus on their party's competence, the ability to manage the economy or provide a stable government.

Opponents of these big centrist parties try to put a wedge between the large parties' voters. That's why it made sense for Labour to campaign on social issues like Church-State relations. It hopes it will get support from Fine Gael voters who are unhappy with the party's unwillingness to take a firm stance.

In a research paper just published, Rory Costello of the University of Limerick has shown the extent to which voters are unrepresented by their party.

He set up a website - whichcandidate.ie - to help voters identify the candidates closest to them on a range of policy issues. By using questions answered by the parties and candidates, and with 23,000 responses to the survey, he matched these to a representative sample of voters so that we can get a sense of where Irish voters lie on a left-right scale and other policy scales.

When asked questions on whether the Government should prioritise tax cuts over spending, or increase the minimum wage, we see that most Irish voters are left leaning.

The graph (below) shows where voters lie. It should be read a bit like you would an OS map, the darker the shade the more voters are in that position. We see Fianna Fail is clearly closest to where the main bulk of voters are. We can also see that on the left is a pretty crowded field, with Sinn Fein the only significant player.

What's really interesting in this research is that on a libertarian/authoritarian dimension there are quite a lot of voters who are unrepresented by their parties. All those small left-wing parties tend to be liberal on the questions about immigration, the expansion of the EU, how crime should be punished. They are pro-international intervention on the environment.

No one represents those people who are left leaning but sceptical on the apparent liberal consensus on these issues of immigration, environment and human rights. They have more traditional views than is fashionable, but they are unrepresented by the parties.

These are the voters we expect to support a populist party - like the ones who abandoned the middle-class Labour party to vote Ukip in the UK. They are the less well-educated working class: 55pc of those who didn't complete secondary school are in that top left position.

Because the survey also asks who people intended to vote for, we can match parties to their voters. More than half of Sinn Fein's voters are positioned as left-leaning authoritarian. They are not represented by the party, which is very liberal on these issues. Sinn Fein can't plausibly move to them. Sinn Fein's nationalism (and Irish nationalism generally) is a 'small-guy nationalism'. We like to see ourselves as the downtrodden - so to be consistent we have to seek to protect the downtrodden.

Sinn Fein does make critical comments on the EU, and it might be that when campaigning at local levels in Leitrim or Kerry, Sinn Fein candidates offer a more conservative message than official policy. Sinn Fein could hardly criticise them for doing this, and possibly encourages it. There are stark differences in the way Sinn Fein positions itself in Northern Ireland.

For those who were surprised by Fianna Fail's resurgence last year, we can see that the party matches closely to its voters. It also matches closely to where the most voters are. Leo Varadkar will soon be Taoiseach, but your money must be on Micheal Martin to follow him to that office.

Eoin O'Malley is a senior lecturer in political science in the School of Law and Government at DCU

Sunday Independent