By this time in the last presidential race, Hillary Clinton had won 672 delegates in the Democratic primaries and caucuses, and Sen. Bernie Sanders (I-Vt.) had won 477. A 40 percent lead with most state contests still to go might not seem insurmountable — except for the Democratic Party's "superdelegate" system, in which hundreds of party leaders and elected officials choose which candidate to back at the national convention regardless of their states' votes. And in early March of 2016, Clinton had collected the endorsements of 458 superdelegates to a mere 22 on Sanders' side. At the end of the race, the gap had only grown, with Clinton's superdelegate count finishing at 609 and Sanders' at 47. The Vermont senator would have had to take huge majorities in the primaries to overcome that advantage. He couldn't do it.
Sanders fans were pissed, and understandably so. They and their champion sought rules changes for the next cycle, and the biggest one they got is that the 771 superdelegates can no longer participate in the first vote at the Democratic National Convention. Yet if no single candidate in that initial round wins a majority plus one of the ordinary, voter-pledged delegates (1,991 of 3,979), superdelegates get to jump in for subsequent votes.
This doesn't necessarily mean Sanders is finished, but it does mean he must win that first ballot at the convention if he's going to win at all. Heading to Milwaukee with a plurality of pledged delegates might have been enough, in a larger field, to fight to victory at a contested convention. Not anymore. Now Sanders needs a 1,991-vote majority.
The math here isn't quite as grim as it was for Sanders in 2016, but it's pretty bad. (FiveThirtyEight put his odds of winning the nomination to one in 30 after Super Tuesday.) Superdelegates have been far slower to endorse this cycle — as of this writing, 530 of 771 have yet to announce their preference. With only Sanders, former Vice President Joe Biden, and extreme longshot Rep. Tulsi Gabbard (D-Hawaii) left in the race, however, those endorsements will likely begin dropping soon. Where will they fall?
Well, Gabbard has a single superdelegate behind her: herself. Sanders so far has 25 endorsements, remarkably similar to his count this time four years ago and barely more than the 24 who backed Sen. Elizabeth Warren (D-Mass.) or the 23 who went for former New York City Mayor Michael Bloomberg before they each left the race. Biden is leading the pack with 104 superdelegate endorsements, including the only active 10 from "distinguished party leaders" — a category of former Democratic presidents, vice presidents, House and Senate leaders, and DNC chairs, none of whom have supported Sanders.
Biden's advantage is far smaller than Clinton's was in March of 2016, but it will only get bigger from here. His endorsements from recently fallen rivals including Bloomberg will probably send their superdelegates his way, a gain of about 40, and possible veep picks like Sens. Cory Booker (D-N.J.) or Kamala Harris (D-Calif.) would each bring some superdelegate endorsements of their own.
Still, Biden is unlikely to need that sort of connection to pick up most of those remaining 530 votes. Sanders has slammed the former vice president as someone "running a campaign that is heavily supported by the corporate establishment," but it's not just corporate leaders who would prefer Biden and the status quo he represents. It's looking a lot like the Democratic Party establishment would, too.
Superdelegates who are also members of Congress or other officials facing a difficult re-election campaign this fall may see their opportunity to put a thumb on the scale for Biden through the lens of self-interest. The GOP will brand every Democrat running as a socialist if Sanders is the party's leader, a very risky label in purple districts. A New York Times report from late last month informed by interviews with 93 superdelegates found these party leaders are thus overwhelmingly "willing to risk intraparty damage to stop [Sanders'] nomination ... if he arrived with the most delegates but fell short of a majority."
That's why Sanders must win the first vote at the convention if he's going to win at all. He's argued superdelegates should back him in the second vote if he has a plurality to avoid the appearance of the party elite stealing the decision from the people. The superdelegate endorsements so far and the Times interviews both indicate that argument is unlikely to prevail.
Instead, superdelegate proportions look to be headed to a similar final spot as in 2016, choosing Sanders' opponent by a margin of five or six to one. The rule change keeps them out of the first vote. But if there's a second vote, it will almost certainly mean an influx of hundreds more delegates who will vote for Joe Biden.