The Italian Liberals of the 20s adopted a “wait and see” approach, leaving the outnumbered socialists, anarchists and communists to fight both the fascists and the loyalists alone. Then when it was clear that the fascists were winning, the Liberals joined them.
I suspect that the 30s Social Democrats of Germany were similarly irresolute (though didn’t join before they were forced to) when dealing with the Nazi threat. Centrists tend to be, whether center-right like the Italian Liberals or center-left like the German Social Democrats.