While the Republicans stare down the real possibility of a contested national convention in July, for the Democrats it’s barely a concern. Why? Thank the superdelegates.

For a Democratic candidate to clinch the nomination, he or she must earn the magic number of 2,383 delegates. It’s possible that neither Hillary Clinton nor Bernie Sanders will earn that number in pledged delegates before the convention—but they don’t have to.

In addition to pledged delegates, the Democrats also have over 400 "superdelegates." Why are they super? Because they can vote at the convention for whoever they want, regardless of how they voted during the primaries.

If at the convention, after a tight primary race, a large enough number of superdelegates decides to switch to one candidate or another, that could push that candidate over the 2,383 mark and win them the nomination. In fact, that's exactly what happened in 2008 for now-President Barack Obama.

Republican superdelegates, on the other hand, are far fewer in number and—crucially—don’t have the ability to change their votes. Since 2015, they’ve been required to vote as their state did in the primaries.

So in at least one scenario, those pesky, complicated superdelegates may come in handy.