A record 12 Democrats to face off in Tuesday's Ohio presidential debate

Twelve Democratic presidential candidates will gather on one stage in Ohio on Tuesday night for their first debate since House Democrats launched an impeachment inquiry of President Trump tied to one of the top candidates, former Vice President Joe Biden, and another leading candidate, Sen. Bernie Sanders (I-Vt.), had a heart attack. Sen. Elizabeth Warren (D-Mass.), meanwhile, is now tied with or leads Biden in the polls. The debate, featuring the largest number of U.S. presidential candidates on stage at the same time, will be hosted by CNN and The New York Times.

Billionaire Tom Steyer is making his first debate appearance, and several second-tier candidates are facing a shrinking window to break through before the first caucus. The other eight candidates in Tuesday's debate are three more U.S. senators — Kamala Harris (Calif.), Cory Booker (N.J.), and Amy Klobuchar (Minn.) — South Bend Mayor Pete Buttigieg, entrepreneur Andrew Yang, former Rep. Beto O'Rourke, former HUD Secretary Julian Castro, and Rep. Tulsi Gabbard (D-Hawaii).

The candidates "are really being distinguished on the same set of issues ... impeachment, what's happening in Syria and a lot of other places," Sean Bagniewski, chairman of Iowa's Polk County Democrats, told Politico. "People are actually starting to look at who would be the best leader in challenging times like these." But with so many candidates facing so much pressure to stand out, there might be some unexpected moments. “Who knows what goofy bulls--t Steyer will pull, or Gabbard will pull,” an adviser to one candidate told Politico.