It could be some months yet before we see the writ being moved for the by election in Dublin South following the early passing of Seamus Brennan. None of the early presumptive candidates from FF/FG/Labour had large votes in the general election last year, so they start from a situation where their personal bases are substantially the same.
With almost 42% of the vote FF should be favoured to win easily here but much of that vote is personal to both Tom Kitt and Seamus Brennan and as such more mobile than might otherwise be the case. FG with 27% would seem next best placed here after FF, but Labour's probable candidate Alex White got marginally more than the presumptive FG candidate in the general and has had a year as a member of the Seanad. That said as a local cllr O'Leary would have been on the ground more often than White and in a bye election the local connection counts.
Fianna fail - Maria Corrigan is in the Seanad and was appointed by the Taoiseach so if elected she can be easily replaced. However, if she does run then you can be sure her relationship with Joe Burke and by extension the former Taoiseach will come up. In that sense she may have first call on the nomination but it could turn out as a negative for her if the election was about another referendum on Bertie.
FG - Jim O'Leary must be favoured, he towed the line when required in shifting wards in 2004 and run an effective campaign as the 3rd option last time out. A safe solid choice.
Labour - Alex White may have to fend off Culhane again for the nomination. There again that may be all done and dusted.
Progressive Democrats - Fiona O'Malley simply has to run, whether for the PDs or more spectacularly for FF.
SF - will run whichever of their council candidate they wish to most promote most Most likely in my view to be Sorcha Nic Cormaic who polled higher last year.
Greens - would be best advised to do as SF will do and run someone just to give them a profile for the locals.
The bookies will favour Corrigan out of the blocks but if you see decent odds from the bookies on O'Leary or White throw a few quid at it or bite their hands off whichever you prefer.