McGovern, Sanders, Trump.
When a party hands control of its nomination process to activists, politically uncommitted voters, and demagogues, the nominees turn out to be creatures of extremes who go down in flames.
That's what Bernie supporters, admitted enemies of the Democratic Party and the center-left views it stands for, want to do at the convention by rules changes to abolish super-delegates.
But not just the professional politicians but much more importantly the nation and the world are safer if our two major parties are not open to outsider or minority takeovers.
For a long time, some people have thought that open primaries made the parties more centrist in outlook because they thought uncommitted voters were mostly centrist.
They were wrong.
The uncommitted have proved to be profoundly alienated people who are far more dissatisfied with the America we have, its economic and political systems, its government, and its party structures, than the people who are registered and regular party voters.
Come to that, the people least dissatisfied with the America we have are registered as Democrats.
They are the ones who support and want to strengthen the modern America built up by over a century of progressivism, and only gradually nudge it to the left in reasonable increments.
And that makes them, in reality, ironically, and despite usage, America's real conservatives.
In contrast, the conservatives as a movement and the Republicans as a party are openly dedicated to repealing all those very same achievements of progressive Americans over that same long century of gradual change, to which they are profoundly hostile, just as quickly as possible.
And the fringe types and outsiders?
On the right, a congeries of conservatives enraged by decades of failure to repeal a century of liberalism, white nationalists, and losers in the global market who demand economic protectionism.
On the left, hyper-liberals who want more and quicker change in the direction of social democracy allied with anti-capitalists, anti-Christians, cosmopolitan globalists, and anti-whites of many stripes.
And all of them are people who loathe "the establishment" and who take up the cry as their very own that "the system is rigged!"