The race to form Ireland's next government kicks off its first full week today. Unlike the lengthy US presidential campaigns, this will be a brief and intense contest.

It had been widely speculated for weeks that November 29 was the preferred election date for Fine Gael leader and outgoing Taoiseach, Simon Harris, carefully chosen to avoid clashing with The Late Late Toy Show on December 6.

When Harris succeeded Leo Varadkar in April, he had pledged that the coalition—comprising Fine Gael, Fianna Fáil, and the Greens—would serve its full term, meaning the election was initially expected early next year. Harris reaffirmed this commitment as recently as early September.

But an earlier election became irresistible. Some will regard this as cheap political opportunism, others as shrewd judgment. Either way, the fact that Mr Harris and his coalition partners were persuaded that now is the right moment to go to the polls is directly linked to two factors: Sinn Féin’s slump; and a buoyant economy, as emphasised by last month’s giveaway budget.

Having been on the front foot for so long, Sinn Féin has seen its support slide in opinion surveys. Last year there was a swagger about the party, when it looked on course to secure more than 30% of the vote and Mary Lou McDonald was being spoken of as a taoiseach in waiting.

But this year has seen a series of stumbles. Support was softening even before the recent series of self-inflicted pratfalls, from the Michael McMonagle and Niall Ó Donnghaile scandals to the curious circumstances of Laois TD Brian Stanley’s departure from the party.

An earlier election became irresistible to Simon Harris and his coalition partners. Some will regard this as cheap political opportunism, others as shrewd judgment

As well as painting Sinn Féin as not being fit for government, the coalition parties will be focusing on how public finances have strengthened on their watch. Around €30 billion of corporate tax income, largely from US tech giants, will flood into the government’s coffers this year - and that’s before another €14bn in back-tax from Apple. It’s an extraordinary amount of money, some of which is being spent on projects in Northern Ireland.

Yet the coalition hasn’t yet managed to use its cash to ease the generally high cost of living or to alleviate the housing problems, which are especially acute in Dublin. And now that Donald Trump is heading back to the White House with his ‘America First’ mantra, there is also the risk that the US tax tap could be suddenly turned off.

Immigration is another vexed issue which the parties and candidates will need to address. Unity should but won’t, be a focus. It would be welcome if all parties were to jointly commit to holding a citizens’ assembly, for example.

This campaign won’t be long, but nor will it be short on drama.