I think this could be called as 1 Election where they was not a single conservative candidate & by then standards all were some degree liberal!
I'm not sure I buy this. It's certainly true that all four major candidates could be broadly categorized as reformers, that all four favored government action to correct imperfections in the existing political and economic society, and that all four were suspicious of the corrupting power of "organized money" but I'm not sure that alone is enough to qualify as liberalism. There is definitely a conservative, capitalist argument to be made for trust-busting and the Federal Reserve Bank; the fact that contemporary conservatives now castigate such policies on the grounds that "government=bad" does not diminish this. I certainly wouldn't brand Debs a "liberal" or bundle him in with the other three, and Roosevelt was deeply conservative on certain issues (most notably war and foreign policy).