With two debates featuring the Republican field already completed, focus shifts to the other side of the aisle Tuesday night when the first Democratic presidential debate is scheduled to take place. Headlining the field, and atop the polls, are former Secretary of State Hillary Clinton and Vermont Sen. Bernie Sanders. 

The democratic debate is scheduled to feature just five candidates, starkly different than the GOP debates that had more presidential hopefuls than one stage would allow. Clinton leads in the national polls, earning about 42 percent of primary voters nationally, according to an average of polls calculated by Real Clear Politics. Behind Clinton is Sanders, who sits at 25.4 percent, according to Real Clear Politics. The rest of the five-person field is filled out by former Maryland Gov. Martin O'Malley, former Virginia Sen. Jim Webb and former Rhode Island Gov. Lincoln Chafee.

Much of the focus will also be on who is missing from the stage in Las Vegas. Vice President Joe Biden is still mulling a presidential run and is not expected to appear at the debate. Despite the fact that Biden has not announced he is running or formed a campaign, he is third in the average of national polls at 18.6 percent and debate organizers set aside a lectern for him should the vice president decide last minute to participate Tuesday.



Clinton will be place at center stage during the debate scheduled to air on CNN at 8:30 p.m. EDT Tuesday. The remainder of the field is placed based on polls from Aug. 1. Sanders will be to the frontrunner's right side, O'Malley will be to her left, with Chafee and Webb on the ends, CNN announced.

With a smaller field, the Democratic candidates can expect to get more time to speak and more direct questions. “You’ll likely see more direct questioning of each individual candidate,” said Jeff Zucker said, president of CNN Worldwide, to the New York Times.