Americans eager to know which Democrat will face President Donald Trump in November's election may have a clearer view after "Super Tuesday" sure to be a defining moment in the race.
Four of the country's 50 states have already voted, but March 3 is the biggest day of the entire presidential primary process, with tens of millions of Americans eligible to cast ballots.
Here are a few things to watch for on Super Tuesday:
Fourteen battlegrounds
The states in play span the nation, from sparsely populated northeasternmost Maine to California, the progressive west coast powerhouse whose population of 40 million is the country's largest.
The southern state of Texas, with 29 million, is another top prize. Virginia, North Carolina, Alabama and Colorado also cast ballots.
The other states in play are Arkansas, Massachusetts, Minnesota, Oklahoma, Tennessee, Utah and Vermont.
With the 14 states - plus American Samoa and Democrats living abroad - reflecting the nation's social and economic diversity, Super Tuesday provides opportunity for candidates to demonstrate their ability - or weakness - to draw from a broad swathe of voters from different backgrounds and across different regions.
Tabulating votes could take all night.