Sen. Bernie Sanders’ upset victory in the West Virginia primary prevents Hillary Clinton from winning the 2016 Democratic nomination just with delegates picked by ordinary Democrats nationwide.

She now needs support from the party’s corps of establishment SuperDelegates to win a majority of the party’s delegates and the nomination.

Hillary Clinton has not been able to secure the Democratic nomination in her race against Vermont Sen. Bernie Sanders. Despite boasting every possible advantage, she has lost 19 state primaries or caucuses to the septagenarian socialist from the northeastern corner of the United States.

Based on past results, Bernie Sanders is likely to win at least a few of the remaining Democrat contests; Oregon, South Dakota, California, New Jersey, New Mexico and Montana. Even if Hillary Clinton were to sweep the remaining contests, Democrat rules for delegate allocations are highly proportional, meaning Sanders will still win a large chunk of the remaining 897 delegates — so denying Clinton a majority of the delegates picked at caucuses and primaries.

Currently, Hillary Clinton has 1,717 pledged delegates, according to GreenPapers, a respected source on the Presidential primary contests. The Associated Press has her tally at 1,716 delegates. Her rival Bernie Sanders has 1,437 pledged delegates.

Pledged delegates, in most cases, are those secured through elections in the states’ Democrat primaries and caucuses. These are the delegates won through the votes of Democrats nationwide voting their state elections.

Surprisingly, given the Democrat party’s egalitarian rhetoric, they are not the only way candidates earn delegates for the nomination, but they most directly reflect the votes of rank-and-file Democrats across the country.

Most media companies show each candidate with more delegates, because they add in the public endorsements of SuperDelegates, a special class of elected Democrats who cast individual votes for the nomination and are unique to the Democrat party.

There are 714 SuperDelegates in the Democrat nomination contest, making up 15 percent of the total number of delegates available. They include elected members of the Democrat National Committee, Democrat Members of Congress and Governors and a special “distinguished” subset of Democratic leaders.

The “distinguished” Democrats given SuperDelegate status is its own class of voters. It includes people like Jimmy Carter and Bill Clinton, who were Presidents. It also includes people like Howard Dean, Al Gore and Walter Mondale who had held high public office. It includes too, though, people like Christopher Dodd, Tom Daschle and Richard Gephardt who had held high office but also currently work as lobbyists in Washington.

In the Republican party, three delegate slots in each state are automatically reserved for the state party chair and the state committeeman and committeewoman to the Republican National Committee. The delegates, however, are generally bound by the results of primary and caucus voting in their state.

Democratic SuperDelegates are altogether different than any Republican counterpart. They represent, collectively, the will of the Democratic Party establishment in deciding the party’s nominee.

SuperDelegates are free to cast their vote for whomever they wish, regardless of the results in their state or district. Their vote is not bound until it is cast on the convention floor. To date, Hillary Clinton has won the backing of 503 of these SuperDelegates, although their votes can change at any time. Indeed, in the 2008 primary, Hillary Clinton had secured the support of most SuperDelegates over Barack Obama until late in the primary, when SuperDelegates began defecting from her campaign to the eventual winner, Obama.

To secure the Democratic nomination, a candidate needs the votes of 2,383 delegates to win a majority. Based on her current pledged delegate total, Hillary Clinton needs to win an additional 666 delegates to secure the nomination. There are only 737 pledged delegates still available through the remaining contests.

Hillary Clinton would have to win more than 90 percent of the remaining pledged delegates to secure the nomination through pledged delegates alone.

Given the remaining number of delegates and party rules for allocating them, Hillary Clinton cannot secure enough pledged delegates to clinch the nomination, even if she sweeps the remaining contests by large margins. In other words, Hillary Clinton can’t become the Democrat party nominee solely on the basis of votes cast by Democrats nationwide.

Hillary Clinton can only secure the nomination on the floor of the convention, dependent on the votes of Democrat party insiders to deliver her the nomination. Interestingly, Bernie Sanders is very likely to have enough pledged delegates that party insiders could make him the Democrat nominee if they swung their support behind him.

The media has fueled itself for weeks game-playing a possible Republican contested convention, where no candidate had the requisite number of delegates to secure the nomination outright. With the end of the Republican primary fight, that scenario is now a historical footnote.

The Democratic party, however, is almost certain to have a contested convention. Hillary Clinton will not enter Philadelphia with the minimum number of pledged delegates to win the nomination. She will only secure it when the SuperDelegates cast their votes and tip the scales in her favor. The very real fact that these SuperDelegates could also cast their votes and make Bernie Sanders the nominee will likely not be lost on Sanders’ supporters.

If Hillary Clinton is the Democratic nominee, as expected, it will only be because party insiders make it so. The votes of individual Democratic voters nationwide will not have spoken.