Former Vice President Joe Biden is the presumptive Democratic nominee for president, but the 2020 primary season is only getting longer — because the public-health threat posed by the new coronavirus keeps delaying primary elections. A grand total of 17 presidential primaries have now been postponed on account of the pandemic.

Since our last dispatch on this topic, four more states have been added to the ranks: Pennsylvania, New York, West Virginia and New Jersey. In addition, five places that had already postponed their primaries rescheduled a second time: Ohio, Puerto Rico, Georgia, Louisiana and Connecticut. All these moves have left us with a presidential primary calendar that is extremely backloaded.

Since March 17 — the last big competitive primary day and the first that really ran up against the coronavirus scare — only three states have wrapped up their presidential primaries. By contrast, nine contests are now slated for June 2, which has become a sort of unexpected mini Super Tuesday. And five primaries are now taking place after June 9, which was originally the last day for states to hold their primaries without penalty.

Given the circumstances, it wouldn’t be surprising if the Democratic National Committee decides to go easy on them, but some of these primaries are really late. Connecticut’s, for example, is now scheduled for Aug. 11, which is just a week before the Democratic National Convention (which was itself rescheduled). And according to presidential primaries expert and FiveThirtyEight contributor Josh Putnam, that would be the latest contest ever in the modern era of presidential primaries.

On the one hand, it’s fair to wonder whether these elections even need to still happen. Sen. Bernie Sanders has suspended his campaign, and Biden is for all intents and purposes the Democratic nominee. But one reason the primaries are still needed is delegates — Biden technically isn’t the nominee until a majority of delegates vote to make him one at the Democratic convention, and primaries decide who those delegates will be. That said, some states, such as Connecticut and New York, do allow presidential primaries to be canceled if there is only one candidate on the ballot. According to Putnam, if everyone except Biden withdraws from those primaries, he would simply get all their delegates. However, the actual elections would still have to go on because …

Another reason is that the presidential race isn’t the only thing on many states’ primary ballots. Indeed, the coronavirus has also forced 15 states to postpone their down-ballot primary or runoff elections as well, many of which were happening the same day as the presidential primary. The most recent states to do so are Virginia, Maine and Idaho, plus four states that hold their presidential and down-ballot primaries concurrently (Pennsylvania, West Virginia, New Jersey and Georgia).

As for the primaries that are still happening in the next several weeks, most are taking a different form. In general, states are moving away from in-person voting and embracing mail voting, but the coronavirus has revealed just how many versions of a “predominantly mail election” there can be. For example, the Maryland and Montana primaries on June 2 have switched to vote-by-mail elections in the “traditional” sense — i.e., all registered voters will be mailed a ballot, but in-person voting options will still be available for those who need them. Reportedly, New York plans to do the same, but so far the only change made to its June 23 primary is that voters can use the coronavirus as an excuse to request an absentee ballot. Meanwhile, in Kansas’s presidential primary and Utah’s down-ballot primary, voters were already being mailed a ballot by default, but normal polling places will now be closed.

At least 11 other jurisdictions are stopping short of mailing voters a ballot, but are mailing them an absentee-ballot application. Of these, Idaho is not offering any in-person voting options, and many counties in North Dakota are closing in-person voting sites as well. The District of Columbia and Rhode Island aren’t eliminating in-person voting, but they are consolidating voting sites, and at least some counties in Iowa will also have reduced polling places. Connecticut, Georgia, Nebraska, New Mexico, South Dakota and West Virginia are — at least for now — slated to operate polling places as usual.

Perhaps the most novel setup is in Ohio, the very next primary on the calendar (voting there ends on Tuesday). The election will be conducted almost entirely by mail, but the state isn’t doing much to assist voters — all they will receive is a postcard with instructions on how to request an absentee ballot. Nor will most voters have the option to vote in person; only voters with disabilities or without mailing addresses will be allowed at a voting center on April 28. No other state has done so little to help voters get their hands on a ballot, so it will be interesting to see what turnout is like in Ohio compared with other states conducting elections under the same conditions.