The Democratic presidential campaign could be decided today in Texas–the nation’s most populous state with one of its most diverse populations. (Candidates have likened campaign there to stumping in five states.)

The Lone Star State also has the most complicated set of voting rules of any state in the union. The document detailing the delegate selection process is thirty-seven dense pages long. Some people call the system the “Texas Two Step.” Others have termed it a primacaucus — a hybrid of a primary and caucus. Whatever you call it, the youth voter group, Why Tuesday?, established to make election reform an issue that our elected pols can’t keep ignoring, has created a new video to explain how Texas really selects its delegates.

And if you want to keep your own delegate tally today as voting unfolds in Ohio, Vermont and Rhode Island as well as Texas, check out Slate’s nifty new delegate counter. Is it possible for Barack Obama to get a majority without the help of superdelegates? Could Puerto Rico’s delegates really decide the nomination? How much would a narrow victory in Texas help Hillary Clinton? The delegate counter knows.