Career
Cobain was first elected to Belfast City Council in 1985. He served as Lord Mayor of Belfast in 1990-1991. He had been an Ulster Unionist Party Northern Ireland Assembly Member for North Belfast since 1998.
Cobain was Chair of the Assembly"s Committee for Social Development and served two terms on the Northern Ireland Policing Board
On 29 December 2007 he was named Administration Member of the Order of the British Empire in the New Year Honours 2008.
After the Christmas 2010 water crisis, Cobain supported a vote of no confidence in Regional Development Minister Conor Murphy, saying "At the end of the day in all of these issues the individual who leads the department is responsible and I have to say if this was any other part of the United Kingdom, or any other part of these islands, the minister would have been away weeks ago..This minister doesn"t appear to accept any responsibility for anything."
He joined the Democratic Unionist Party saying the UUP was "riven with personal and policy divisions" and was "politically exhausted". Cobain was co-opted on to Carrickfergus Borough Council as a councillor for the Carrick Castle area.
He ran for the Democratic Unionist Party but failed to be elected to the Mid and East Antrim Borough Council in the May 2014 Elections.