And the famous paradox of democracy is how to give the people enough power to protect themselves from the state, without giving them enough power to vote themselves endless largesse from it. As Cicero warned 2000 years ago, popular government lasts only until the electorate discover their votes are the key to the treasury. So the two tasks of social democracy are first to do what the people want and second, not to make more individually attractive promises than can be paid for in total without imposing a crushing burden on society. And it is the latter task that is the difficult one. The national restraints on government were largely destroyed by bad jurisprudence in the 1930s, but worked for 150 years, which isn't bad.
Parliamentary systems face the same problem, but handle it differently.
We didn't quite reach that point in the 1980s, but what went wrong in the Trudoney years is certainly not that government contemptuously ceased to heed the electorate's clamour for free money. Rather, it handed it out in such quantities on such feeble pretexts that the treasury was torched. There is some excuse for western Canadians not seeing that, because the minority of voters who live there tend to hold different political beliefs from the majority further east. But the problem with, say, the National Energy Program, is not that it failed to reflect majority opinion but that it failed to protect minority rights against the majority, who wanted cheap energy and voted in a party that promised it. It's not clear that pure populism can be implemented, partly because the leader must do both what party members want and what the people want.