I’ve read and heard a lot of comparing Bernie Sanders’ 2020 campaign to Donald Trump’s 2016 in this respect: In both cases, you’re looking at a party outsider popular enough to get not a majority of votes but a respectable plurality, and the party couldn’t unite to block it. The Beast’s own Matt Lewis wrote a smart take on this just the other day.

One should be careful in comparing Sanders to Trump. Sanders is not a Democrat, but at least he has been in Congress a long time and has caucused with the Democrats all that time. So he didn’t just materialize out of nowhere as Trump did.

Also, he’s not an amoral gangster. He’s a humane and decent person.

But having said all that, the comparison is apt in the narrow electoral sense. In 2016, there were big figures in the Republican Party who were freaked out about Trump being the nominee. Today, there are big figures in the Democratic Party who are freaked out about Sanders being the nominee. Republicans suffered from a “collective action” problem then, in that they could not get their mainstream candidates to unify behind one among their number. Democrats suffer from the same problem today. Is the “centrist” going to be Pete Buttigieg, Amy Klobuchar, Mike Bloomberg, or Joe Biden?

So it’s the same. Except—potentially, it’s worse. Why? Because of the delegate formulas. Let me explain.

As we all know, at the end of the day in American presidential primary contests, it’s not the votes that matter, it’s the delegates. And a lot can change depending on how delegates are awarded.

You might remember that the Republicans changed their rules after 2012, when the Mitt Romney-Rick Santorum face-off dragged on longer than the party poobahs preferred. All this stuff is very complicated and technical, but basically what they did was to change the rules to try to get a nominee faster in 2016. They obviously didn’t know when they did this that they’d have a Donald Trump problem.

So there was some front-loading of some big states. Some states went winner-take-all, meaning (more or less) just what it sounds like. Some states went winner-take-most, in which the winner got an extra batch of delegates. Some went “proportional with a winner-take-all chance.” Others went proportional. It’s all described here.

The long and short of it is that under 2016 Republican rules, the winner got more delegates than he was proportionally due. Trump won 45 percent of all the votes cast in all GOP primaries and caucuses. But he got 70 percent of the total number of pledged delegates. He hit the “magic number” of 1,237 delegates in late May, after he won South Dakota.

The Democrats, of course, with their concern for being fair and giving everyone a participation trophy, don’t do it that way. All Democratic delegates are awarded proportionally. (I snark a little, but this is in fact the plainly fairer way.) Naturally, it’s much more complicated than that. Some delegates are awarded based on statewide totals, others on totals within the particular congressional districts.

But the bottom line is this: The Democratic system is much closer to real proportionality. Yes, there is a threshold that candidates have to hit to get any delegates at all, 15 percent. But the way this race is shaping up, it's not crazy to think that four or five candidates could hit that threshold in most states.

In other words, nobody in this year’s Democratic primary is going to replicate Trump’s feat of getting 45 percent of the vote and 70 percent of the delegates.

And what’s the upshot? It’s this. Let’s say Sanders keeps cruising along and getting his 25 or 30 percent. This seems to most people like his ceiling. Now, it might not be. If he wins a few big ones or a few unexpected ones on Super Tuesday, momentum might swing in his direction and he might start getting bigger percentages. But let’s just say for argument’s sake now that he stays around his current ceiling.

If so, he’ll win maybe around a third of the delegates. There are 3,979 pledged Democratic delegates this year (and 771 super delegates, whom we’ll get to). One-third of 3,979 is 1,326. The magic number for the nomination is 1,991. So, it’s not particularly close.

Which means that, assuming it remains a multi-candidate field and candidates keep winning with fairly small pluralities while a few others hit that 15 percent threshold, the Democrats could have a total mess of a situation in delegate terms by the time the voting ends in June. Imagine something like Sanders 1,300; Bloomberg 1,000; Klobuchar 900; Buttigieg 800.

Sanders would be ahead, obviously; but would he be ahead enough to convince the super delegates (elected officials, party committee members) that they had to go with him? I doubt it. This constitutes getting ahead of ourselves, but I think he’ll need a bigger lead than that.

Anyway I’m obviously just making those numbers up but the point is this: The Republicans’ 2016 collective action problem could not stop Trump, but at least their process gave them a clear consensus candidate before the voting was done. The Democrats’ process may be doomed to prevent the party from having such a candidate, and then it will be on to a hellish convention.

Can you picture Bernie Sanders and Mike Bloomberg, neither a Democrat to begin with, trying to negotiate peace? We're in trouble.