The constituency divides neatly into two. Barry, the main town, is a Labour stronghold. The bluer Vale has the air of a detached piece of the Cotswolds populated by Cardiff fat cats and replete with four-by-fours parked outside wine bars in the market town of Cowbridge.
Mr Sweeney remains calm in the face of oncoming nemesis. "My impression is that very few Conservatives have defected," he says. Ten would be enough to see Mr Smith back at Westminster.
Overall Tory prospects in Wales looked dim. In 1992 the party won six of the 38 Welsh seats. Labour took 27, Plaid Cymru 4 and the Liberal Democrats 1. Boundary changes have added two new seats, both likely to be Labour.
Since 1992, it has been downhill all the way, polls suggest, and no Tory seat looks safe. Not even Clwyd West, where boundary changes give Rod Richards - who last year resigned as a junior Welsh Office minister over allegations of an extra-marital affair - a notional majority of 7,313.
Interesting three-way battles are in prospect in Conwy where the Tories are defending a majority over the Liberal Democrats of 995, and Brecon and Radnorshire where speculation is rife over Labour and Liberal Democrat claims that they will be the one to oust the incumbent Tory, Jonathan Evans, whose majority in 1992 was 130. Ceredigion, held by Plaid Cymru's Cynog Dafis who came from fourth place in 1987, to win by 1,893 five years later, is also up for grabs.
The Liberal Democrats' sole Welsh MP, Alex Carlisle, who has represented Montgomery for 14 years, is standing down and although his successor, the Estonian-born Lembit Opik , is expected to hold on, Paddy Ashdown's Welsh troops have a lot to make up following the loss of two seats in the last election.
The contest in Newport East has been enlivened by the presence of Arthur Scargill. The Socialist Labour Party's leader is standing against the former Tory Alan Howarth who crossed the floor to join Labour in 1995. He is by all accounts being well received, not least for what is seen as his courage in making his dramatic switch.
The Tory strategy is aimed at rubbishing Labour's proposed Welsh Assembly. A recent Western Mail poll found only 41 per cent of those questioned supported a Welsh assembly.