Andrew Lynch: Fianna Fail and Fine Gael cannot remain apart much longer
Eamon de Valera and Michael Collins must be spinning in their graves.
Over 90 years since the Civil War ended, it looks as if the two sides are finally prepared to kiss and make up.
Michael McGrath, Fianna Fail's finance spokesman, has signalled for the first time that his party should swallow its pride - and serve as junior partners in a Fine Gael-led coalition.
It may be the political silly season, but McGrath's comments make an awful lot of sense.
As he points out, opinion polls show that Fianna Fail are highly unlikely to overtake Fine Gael's number of Dail seats after the upcoming general election.
Therefore, he admits, it would be "out of touch and arrogant" for the Soldiers of Destiny to insist on staying out of Government Buildings until they can be top dogs again.
Within Fianna Fail, this makes McGrath the equivalent of a Catholic bishop who says that priests should be allowed to get married. Many of the party's grassroot members agree with him - they are just not supposed to say so in public.
His suggestion certainly contradicts the teachings of Pope Micheal Martin, who regularly condemns Fine Gael as a bunch of heartless right-wingers who are politically untouchable.
However, since McGrath is a frontrunner to become Fianna Fail leader himself in the near future he cannot be so easily dismissed. If his vision of a partnership with Fine Gael takes hold, it would transform the next election campaign.
It would also change Irish politics for good - leading to the sort of left-right party divide that is standard in most other European countries.
Now that McGrath has stretched a hand of friendship across the political divide, it will be interesting to see if anyone grabs it.
Simon Coveney, a likely contender for the Fine Gael top job when Enda Kenny quits, set some hearts racing earlier this year when he declared, "I think there's a lot of good people in Fianna Fail ... I don't have any ideological problem with forming a coalition with them."
Leo Varadkar, Coveney's biggest leadership rival, has said that a FF-FG alliance would feel like gay marriage - a bit strange at first, but would quickly be accepted as completely normal.
Like many politicians who do something outrageous such as telling the truth, Simon and Leo were quickly ordered by their colleagues to shut up. Something similar is happening to Michael McGrath this week.
In the long run, however, their views must prevail - because they are more in touch with an electorate that sees the old Civil War divide as completely irrelevant to 21st century Ireland.
Of course, the precise difference between Fianna Fail and Fine Gael has always been hard to explain.
Former Taoiseach Sean Lemass used to sum it up as: "We're in and they're out."
In fact there are ways to tell the two parties apart, even if they are not often visible to the naked eye.
On a basic level, Fine Gael voters tend to be more middle-class and financially conservative. Fianna Fail people are usually less socially liberal but greener on the idea of a united Ireland.
Even the most fanatical Soldier of Destiny or dyed-in-the-wool Blueshirt, however, has to accept one awkward fact.
For over four years now, Fine Gael have been implementing the exact same economic programme that Fianna Fail negotiated with the Troika shortly before they were booted out of office in 2011.
Enda Kenny and Micheal Martin may appear to despise each other, but in pure policy terms they are closer together than any two other Dail leaders.
If a Martian landed at Leinster House tomorrow, its first question would not be why these parties are on opposite sides - it would be why don't they go the whole hog and announce a full-blown merger?
With a general election coming up fast, more and more political big beasts are starting to play fantasy coalitions.
Michael McGrath's Fine Gael-Fianna Fail paper team is one that feels like it might actually become a reality - and when better than the centenary of 1916?