The polls suggest she is going to lose her seat, but the polls at this stage in the 1999 election said much the same thing, and they were wrong.
How strongly she polls in the first count and where her transfers come from could well decide who goes to Europe for this, the largest constituency in the country.
The region has a history of favouring independents and in the last European election, the old Connacht-Ulster constituency divided the first preference votes almost evenly between Fianna Fáil, the four independents and the rest.
The same two strong independents Dana and Marian Harkin meet again, but according to the Irish Examiner Questions and Answers poll, Ms Harkin is polling double that of her opponent.
A strong independent in the past has deprived Fianna Fáil of a second seat and it could do so again, unless Galway-based Dana is eliminated and enough of her votes from the region's largest urban area go to the other Galway candidate, FF MEP Seán Ó Neachtáin.
Whether Ms Harkin can hold her current lead is uncertain. Roscommon will prove to be an important part of the constituency with no local candidate, and already it has become a battle ground for Fianna Fáil.
Campaigners on the ground say Dana's name arises frequently on the door steps, even though her posters have only gone up over the weekend. They are hearing very little about Ms Harkin, but the opposite is the case in Donegal and even closer to the Border area of Cavan, Monaghan and Leitrim despite Ms Scallan's Derry roots.
However, the well-matched performances of the two Fianna Fáil candidates may not be to Dana's advantage. She got a good share of Pat the Cope Gallagher's surplus and Noel Tracey's elimination votes last time around. The longer the FF candidates remain in the contest the more likely she is to fall behind.
Should Dana be eliminated early, her votes are expected to go all over the place but mostly to Fianna Fáil and to Ms Harkin. The proportions could prove vital in deciding if Ms Harkin takes a seat. The Border area is proving a stronghold for Sinn Féin candidate Pearse Doherty. Seán McManus got 20,000, just over 6%, last time for the party, but their organisation is much stronger and more widespread this time and their campaign has been on the road for longer.
He will need to get about 18,000 votes from his native Donegal and from Cavan and Monaghan if he is to keep his hopes alive of tying for the third seat.
This should be possible given that they already have about 22 sitting local representatives in Cavan-Monaghan. Picking up the other 40,000 or so votes will be a challenge. The party hopes this can be done through their strategy of integrating the local and European campaigns with Mr Doherty turning up at every local election launch for the past two months.
The addition of Clare to the constituency could well be to Sinn Féin's advantage also as they have a substantial following in Shannon and Ennis. Fine Gael is running two candidates to replace outgoing MEP Joe McCartin from Leitrim. There has always been a Fine Gael seat in the old Connacht-Ulster constituency and many believe this will not change. Today's poll shows FG just 1% ahead of the 20% they polled in 1999.
Senator Jim Higgins from east Mayo has always been favoured over former TD Madeline Taylor-Quinn. However, since she is the only candidate from Clare her transfers could help Senator Higgins secure the third seat.
Seán Ó Neachtáin will be looking to Clare's 103,000 Fianna Fáil votes for the margin he needs if he is to pull ahead of Mr Doherty and, possibly more importantly, of Dr McDaid in first preferences.
Fianna Fáil managed to win two seats in the old constituency in 1984 and again in 1994 but with 42% of the vote. A strong independent upset this in 1989 when former FF Neil Blaney took 16% leaving FF with 32%, and again in 1999 when Dana took the same percentage leaving FF again with 36%.
They believe they could take two seats this time but if Marian Harkin manages to take the 16% share as predicted in the poll, the Fianna Fáil seat could go to their strongest candidate on the day with the third going to Fine Gael Senator Jim Higgins. He would take over from retiring MEP Joe McCartin from Leitrim.
The dog-fight between Spiddal teacher Mr Ó Neachtáin and Dr McDaid appears to be paying dividends. The row continues between them over splitting the constituency, with both of them tugging at Roscommon.
The junior minister hopes to build on his profile as former minister for sport and for tourism.