The huge student movements of the 1960s largely bypassed the NUS, which activists wrote off as both irrelevant and hopelessly right wing.
At a local level, most university student unions resembled little more than a club with an inbuilt Tory majority.
That situation began to change in the early 1970s when the Tory government proposed a series of attacks on the NUS that even traditional union-based clubs and societies felt obliged to object to.
This was combined with a dramatic fall in the level of the student grant, which led to national campaigns in 1972 and 1973. Huge demonstrations were backed by rent strikes and occupations that spread from college to college.
The impact of this national movement was to find an expression in the NUS, as right wing leaders with a history of association with the CIA were dumped in favour of Communists, Labour left wingers and some revolutionary socialists.
From then on NUS was pushed into debating positions on all manner of subjects, and sometimes into the national coordination of student struggles.
Students who wanted their unions and the NUS to give leadership to the various battles over funding cuts, oppression and poverty often found themselves having to battle even the new left leaders of NUS to get it.
But the recent memory of successful struggles did at least make it a fight worth having.
While the social make-up of students today is far more varied than it was in the 1970s, many student unions have more income than their predecessors, but are apolitical and divorced from the needs of most.
The battle to change these must start by building campaigns on campuses that seek to bypass the union bureaucracy by appealing directly to the growing political radicalisation that exists in every university.