A blue wave has surged in the United States. It has been a week since the Democrats hammered the Republicans and regained majorities in the House and the Senate, and the credit for that is, shall we say, a matter of debate.

Success has many fathers. One of them is Barack Obama , the first to break the kind of barriers a new generation of Democrats has overcome. This week, I follow what can and cannot be traced to the man who still holds a unique position in the liberal political imaginary , almost a decade after leaving the White House.

Politicising moment … Barack Obama stands with his wife, Michelle, and daughters Malia and Sasha during election night in November 2008. Photograph: Joe Raedle/Getty Images NA

Barack Obama’s presidency and specifically his first election win, remains a formative politicising moment for many millennials. Few imagined that a Black man with an Arab Muslim middle name, and an electrifying agenda of hope, could become president of the United States.…