I don't think enough people get benefits, nor do enough make a direct connection between their vote and social policy for this to add up.
Are you kidding? Everyone with kids gets benefits, just to start. Trudeau was nowhere in the last election until he came out with his new slew of promises to cut taxes to the 'middle class', and offered up a number of big spending promises. Why do you think the whole of Atlantic Canada voted Liberal? It was because the Liberals promised more welfare (they call it EI out east) than anyone else.