The connection between the DUP and loyalist paramilitaries is long and well-established - going right back to 1959 when Paisley was instigating riots across the North - to 1974 when he orchestrated the UWC strike imposed by the UDA and the UVF - to the dozen of 'third forces' (cover names for the existing loyalist paramilitary groups) to drive the 'Catholic enemy' out of Northern Ireland.- to cheerleading for one of the worst loyalist psychopathic killers in Billy Wright (who wanted to be known as 'King Rat') who was the best of 'friends' with leading DUP MP Willie McCrea. Wright's battle cry was "Yabadadoo, any Taig [Catholic] will do". McCrea shared a loyalist platform with Wright in 1996 after the Combined Loyalist Military Command issued a death threat against Wright (because he was too much of a nutcase even for them). During the Drumcree standoff in 1996 Wright drove a JCB with a fuel tank in the digger bucket into the curchyard at Drumcree and threatened to spray the police with petrol and set them on fire if the didn't allow an Orange Order parade down the Garvaghy Road. Wright's family was legally represented by another DUP MP Danny Simpson after he was murdered in prison by republican paramilitaries (something that turned him into a loyalist martyr - and an utterly stupid thing for republicans to do).
The DUP have one objective and one objective only - that is to maintain it position in Northern Ireland as the largest unionist party and their position of being bigger than Sinn Fein. If a hard Brexit serves their interests in doing this then they will absolutely support it - and that is very likely as Sinn Fein have been using the Brexit vote for their own political motives to push for a border poll in the North (a referendum on a united Ireland). If a hard Brexit suited Sinn Fein then they would have no problem supporting it - but a hard brexit means a hard border between North and South so SF are opposing brexit because they view it as making a united Ireland more difficult to achieve.
