Why has the SDLP declined?
The SDLP was founded in 1970 and its origins lie in the Northern Ireland Civil Rights Association. It has never been violent or supported paramilitary groups. It has been active in all peace initiatives put forward by the British government and naturally supported the Good Friday Agreement (Hume even won a Nobel Peace Prize). In 1998 the SDLP won 24 seats, which made them the largest Nationalist party, and Seamus Mallon became deputy First Minister.
However, since then they have been in steady decline, and in 2003 ceased to be the largest Nationalist party. This was evidenced in the most recent assembly election when they got 12 MLAs which is a decrease of two from last time. They have also declined in Westminster, as currently they have 3 MPs to Sinn Fein’s 4. They also have no MEPs. There are many reasons for this decline, the first of which is how they effectively lent votes during the ceasefire.
When SF were banned from the North/South Ministerial Council the SDLP criticised the exclusion and said it was ‘not helpful’ for the workings of the Assembly. In July 1999 Mallon resigned as deputy First Minister in an attempt to hasten progress on decommissioning. The SDLP were instrumental in bringing Sinn Fein into devolution, but ironically the more the SDLP move things forward the more votes they lose to Sinn Fein. The failure of the first Assembly very shortly after it began, damaged the SDLP who were dominant on the Nationalist side and had the top power sharing positions with the UUP.