CHICAGO — If the futures markets are to be believed, the Democratic Party of 1928 — pardon, 2028 — enters its nominating contest without a commanding favorite, its presumptive standard-bearer holding only a 25 percent probability of securing the prize. The dispatch from tomorrow is not one of coronation but of contest. The party faithful, it seems, are still very much in search of their man — or woman — for the hour.

Polymarket, which recorded nearly five million dollars in trading volume on this question in a single day, places the leading Democratic contender at one-in-four odds — a figure that speaks less to that candidate's weakness than to the extraordinary uncertainty roiling the field. In open conventions of memory, dark horses have ridden to glory on far thinner odds. The stakes could scarcely be higher: whichever Democrat emerges from this scramble must carry the banner against a Republican Party that will have had years to entrench itself.

A single galvanizing event — a policy crisis, a generational speech, or the strategic withdrawal of rival contenders — could rapidly consolidate the field around one name and send these market numbers soaring.