I suppose even Ereignis can become a flogged dead horse, although we haven't gone quite that far yet. You can look at historico-political events -- say, of the 1930s -- from the perspective of Ereignis, by which I mean, from the perspective of the "step back" from metaphysics, but Ereignis itself cannot be thought from these events because it has to be thought first of all in its own right as a stage in grappling with the deepest issues in Western thought itself. So, on the one hand, Nazism can be viewed through the metaphysics of Nietzschean will to power but, on the other hand, will to power characterizes the entire epoch of subjectivist metaphysics starting with Descartes (its seed lying already in Aristotle's ontology of 'powerful', 'efficient' movement/change). The will comes more and more to the fore in the metaphysics of Descartes, Leibniz, Schelling, Schopenhauer, and finally Nietzsche.
With cogito ergo sum Descartes posits human being AS subjectivity. Henceforth the human being under-lies all movement/change, and strives to master all movement/change through modern (mathematized) scientific means. On THAT score, National Socialism and the caring welfare state are the same. To differentiate between the two, as a thinker, you cannot simply proceed self-evidently from your own 'liberal' or 'progressive' political convictions, criticizing Heidegger's anti-modern anti-liberalism along the way. Rather, the issue of FREEDOM is posed philosophically and it has to be penetratingly asked wherein free human being lies as a (possible, future) historical mode of worldsharing. That freedom and democracy are usually treated as synonyms these days is a scandalously complacent thoughtlessness, in my view. If human being 'gets over' ('verwindet' rather than 'überwindet', 'overcomes') being the under-lying subject of all presencing and absencing in stepping back from the metaphysical will to effective power in linear time, what could freedom look like in the open, three-dimensional free play of the time-clearing?
First version posted on the An und für sich blog.
The issue of freedom in worldsharing is dealt with in more detail in my Social Ontology.