South Antrim: A two-horse race in a first-past-the-post election should be a simple affair - but not in South Antrim.
Even when the two horses are from the unionist stable and both claim to be anti-agreement.
David Burnside, the sitting Ulster Unionist MP, and the Rev William McCrea, his DUP challenger, face each other for the third time in this solidly unionist constituency flanked by other solidly unionist constituencies.
Each has defeated the other once already in an election.
Before boundaries were redrawn, Lord Molyneaux, the former UUP leader, held this seat with 35,000 votes to spare.
Mr Burnside, canvassing the Carnmoney area just north of Belfast, is convinced unionist divisions are pushing down the turnout to the detriment of unionism.
"Nearly 50 per cent of these people will probably not vote," he says.
"They are sick of unionist in-fighting and candidates gutting each other.
"A united unionist ticket would put the vote up 15 per cent."
Mr McCrea questions the Burnside position on the agreement, portraying his opponent as a flip-flopper whose genuine beliefs are hard to pin down.
He's had a busy day campaigning in Ballyclare and in Antrim town aboard the party's high-visibility battle bus.
"Mr Burnside propagated the agreement, voted for it and campaigned for it. So he's pro-agreement.
"However, he found that was unpopular, so in the last election he was pro-agreement at some doors and anti-agreement at other doors, Mr McCrea said..
"Under the Belfast Agreement terrorists were put on to the streets, the RUC was destroyed, terrorists were put into government over the people that some of them planned the destruction of and [ there were] unaccountable all-Ireland bodies."
That's what David Burnside supported, Mr McCrea tells the electorate. "He can't wash his hands of that."
Mr Burnside can't claim to be anti-agreement when his party leader is not, he goes on.
There can be no such doubts about the integrity of the DUP stance.
The UUP man says: "I have a broad pluralist approach, yet I'm hardline on the agreement."
He asks pointedly of this reporter: "You have just been with me for an hour around the doors of this constituency. Who mentioned the agreement?"
As far as he is concerned, the agreement has been tried, failed, "and I don't want it put together again".
There will not be an inclusive Executive at Stormont, he insists. "I don't want Sinn Féin in it at any price. They have lied and been duplicitous and I will not leave the door open or throw them a lifeline at Stormont.
"In some ways the DUP is almost offering more of a door-open policy to Sinn Féin than I would do."
He cites his unionist credentials - he once stood for Bill Craig's Vanguard unionists in 1973 when a student.
He has served in the British army. RUC emblems hang on his office walls and are emblazoned on his tie.
His mobile phone rings out "Scotland the brave".
Yet the DUP alleges that the Ulster Unionists are more against their democratic brethren than against the nationalist SDLP.
Mr McCrea points to David Trimble's call for a centre-ground voluntary coalition with the SDLP which could seize power at Stormont pushing the DUP and Sinn Féin to the margins - just as things were before suspension.
Traditional unionists wouldn't do such a thing, he says.
It is difficult to see how Mr Burnside's desire for a greater measure of unionist unity, and Mr Crea's call for his opponent to be true to his vocation will affect the outcome.
What could have a more direct impact will be the votes of supporters of Alliance and SDLP. Though relative small in number, such voters have significantly influenced the result here in the past. Alliance is insisting it is campaigning on its own terms and not telling its supporters to vote UUP to keep the DUP out.
Party leader David Ford held on to the sixth and final seat here in the 2003 Assembly poll and is unlikely to change his call for voters to rally around him.
Noreen McClelland, the SDLP candidate and wife of the former Assembly member for the area, is also not expected to push nationalists to vote tactically for Mr Burnside, given his proclamations against the agreement.
Also unknown is how Sinn Féin's Henry Cushinan will fare in his effort to repeat the notable level of support won at two previous polls by Martin Meehan.
There is no threat to the unionist domination of this constituency, which leaves pro-unionist voters free to choose between candidates without fear of handing over the seat.
Their decision could be telling.