After Parkes was dramatically altered in a redistribution, Cobb ran for the neighbouring seat of Calare at the 2007 election after the popular independent member Peter Andren retired. The Liberal-National Party Coalition lost the election, but Cobb won Calare handily. He was chosen by new Opposition leader Brendan Nelson to be a member of the shadow ministry, as the spokesperson on regional development and water security. He was re-elected at the 2010 election and in September 2010 was appointed Shadow Minister for Agriculture and Food Security by Opposition leader, Tony Abbott.