The not-terribly-well-known Seth Moulton and Tim Ryan prepare to strut their stuff at an Iowa event know as an incubator for Democratic presidential candidates. Photo: Bill Clark/CQ Roll Call; Tom Williams/CQ Roll Call

It’s the early, silly season of 2020 presidential speculation. So there’s nothing unusual about speculation surrounding two fairly obscure Democratic House members, Seth Moulton of Massachusetts and Tim Ryan of Ohio. Compadres in an unsuccessful revolt against Speaker Nancy Pelosi last November (Ryan was the alternative candidate, Moulton a vocal supporter), they have both already attracted rumors that they’ve seen a future POTUS in the bathroom mirror. They will join another colleague who has attracted some national attention, Cheri Bustos of Illinois, as featured speakers at September’s Polk County Steak Fry, in Des Moines. This event is an effort to revive the annual Steak Fry event former senator Tom Harkin used to host in his home town of Indianola, which was a big-time magnet for future Democratic presidential candidates.

Everybody should get used to the idea of a putative 2020 Democratic field the size of an Iowa cornfield. There are three potential candidates who would each become front-runners in the 2020 race if they decide to run: Bernie Sanders, Joe Biden, and Elizabeth Warren. There are questions as to whether any or all of them are too old, particularly for a party looking to show it’s shed the barnacles exposed by the 2016 Clinton campaign. Sanders will be 78 when the 2020 Iowa Caucuses are held; Biden will be 77, and Warren will be 71 (for that matter, Donald Trump will be 73). But none of them has any particular reason to diminish their influence by declining interest in 2020. Their long shadows will make it harder for little-known alternatives to emerge. But the possibility of retirement or illness among the Big Three keeps open the gate to dark-horse fantasies.

If Sanders, Biden, and Warren do fall by the wayside, Democrats may suddenly find themselves with a presidential field that resembles the mob that ran for the GOP nomination in 2016. And as National Review’s Jim Geraghty reminds us, that did not work out to well for those Republicans who kept expecting someone to emerge to knock off Donald Trump, right up to the moment he was nominated:

One chunk of the field convinced itself there was an “establishment lane,” leaving Jeb Bush, John Kasich, Marco Rubio, and Chris Christie all elbowing each other for the same base of support that proved insufficiently influential. On the other side, Ted Cruz, Rick Perry, Bobby Jindal, and Scott Walker tried to occupy the “conservative lane.” Ben Carson and Carly Fiorina competed with Trump for an “outsider lane.” But in the end, it turned out there were no real lanes, just a traffic jam. Every non-Trump candidate’s determination to be the last one standing against Trump was the strategic miscalculation of the cycle.

There is no Donald Trump analogue gearing up for a presidential run on the Democratic side in 2020, so far as we know. But if one emerges, she or he will be helped enormously if there is a large field against which to pose as Gulliver among the Lilliputians. Geraghty counts 18 possible candidates right now, and while some will certainly not run, others may come out of the woodwork if the Big Three give the race a pass. Indeed, the Trump precedent has made the narcissism of long shots seem a lot more reasonable.

There are some things about the Donkey Party’s procedures that might help mitigate the risk of an accidental nominee. Most importantly, Democrats award delegates on a strictly proportional basis, making the occasional sweeps that helped Trump win in 2016 impossible. The Democratic practice of awarding nonelected “superdelegates”— if they preserve it — is also a hedge against a hostile-candidate takeover of the party.

But even if they have no reason to fear the fate that befell the GOP in 2016, Democrats should begin to think through the practical consequences of a very large presidential field. If nothing else, the two-tier debates Republicans were forced to undertake would be very controversial in a party where last year’s debate scheduling and formatting were a huge bone of contention. And an undifferentiated glut of candidates might be good for party unity but not so hot for voter interest.

Maybe one or two of the Big Three (it’s hard to envision all of them running) will enter the 2020 race and either lock up the nomination early or at least cull the field of electoral weaklings. If not, then just two short years from now, at the Iowa State Fair, the candidates may be so thick on the ground that you won’t be able to stir ’em with a stick.