Former Chicago mayor Rahm Emanuel said Sunday that Democrats are better off appealing to swing voters with a reasonable candidate than committing to a strategy of turning out progressive voters by nominating Sen. Bernie Sanders (I., Vt.).

"Here's what I think is a real challenge for Democrats on the eve of Iowa: What is the bigger threat for our party? Are we going to nominate somebody that can't win, or are we going to risk a rupture in the party that is irreparable?" he said. "In 1992, '96, 2008, 2012, and in 2018, the Democrats showed a formula for winning nationally. The question is are we going to follow that formula or throw the playbook out and try something different?"

Emanuel said Sanders is playing the same political game as President Donald Trump by focusing on his base.

"I'll say one thing about Bernie Sanders: His playbook is no different from Donald Trump's," Emanuel said. "Both rely on the fact that you don't need fickle swing voters, that if you just talk to your base and energize the people that should vote for you, you can win."

He also argued that the Sanders strategy could lead to losing Electoral College again because Democrats will have focused on energizing already committed progressive voters instead of getting swing voters.