Hillary Clinton, Bernie Sanders and Martin O’Malley will face each other Tuesday night on CNN in the first Democratic debate for the party’s presidential nomination.

Two other candidates will join them on the stage; however, many see this as a battle between the former secretary of state and the Vermont senator.

At 8:30 p.m. ET Tuesday, Clinton, Sanders, O’Malley along with former Virginia Sen. Jim Webb and former Rhode Island Gov. Lincoln Chafee will stand together on stage in Las Vegas in front of millions of Americans. Issues important to the Democratic base will be more than likely discussed, including immigration reform, justice reform, climate change, and gun control. However, foreign policy and other social issues could also be touched upon.

The debate could also make Clinton an easy target after her recent flip-flopping on key issues to the Democratic base: TPP and the Keystone pipeline. In the days leading up to the debate, Clinton has switched her stance on President Barack Obama’s legacy trade deal, which many progressives argue would hurt American workers.

Yet, former Secretary Clinton leads in most polls, including in Nevada, but Sen. Sanders could outshine her in the debate and push further ahead among voters. A poll conducted by CNN and ORC International released on Monday shows Clinton with a clear lead over Sanders. She got 50 percent while the Vermont senator only won 34 percent. These results, however, include Vice President Joe Biden, a rumored potential late entry. Without Biden, Sen. Sanders fares even worse. He receives only 36 percent while Clinton jumps to 58 percent.

O’Malley, Chafee and Webb appear only as mere asterisks on the poll.

Vice President Biden, on the other hand, was no afterthought, according to the poll. Twelve percent of respondents favored him even though he has not announced his intention to run.

CNN invited him to participate in the debate but Biden turned them down, opting to spend time with his family in Delaware to decide whether he will run or not, according to the New York Post. He will announce his decision after the debate. CNN remains hopeful nonetheless.

Jim Acosta, CNN senior White House correspondent, tweeted a photo of an extra podium brought in case Biden changes his mind at the last second.

Speaking of the podiums, on Sunday CNN announced in what order the candidates will be standing. Clinton will be at the center flanked by Sanders and O’Malley to her right and left, respectively. But to the viewer Sanders will stand to her left.

Webb will stand next to Sanders and Chafee next to O’Malley. Both of these candidates are running on slightly different platforms than the poll leaders. Chafee advocates peace while Webb supports a continuation of our current geopolitical status with some alterations. Chafee calls for raising the minimum wage while Webb calls for tax reform.

All of these topics and others are likely to be brought up by the debate’s moderator, CNN anchor Anderson Cooper. Dana Bash and Juan Carlos Lopez will join him, asking question as well. The debate will feature a social media component, allowing viewers to ask questions via Facebook and Instagram. Don Lemon will ask these questions.