Biggest blow to Clinton came from Midwest Obama voters who backed Trump, says progressive strategist

The biggest blow to Hillary ClintonHillary Diane Rodham ClintonFormer Obama adviser Plouffe predicts 'historical level' of turnout by Trump supporters Poll: More Republican voters think party is more united than Democratic voters Whoopi Goldberg presses Sanders: 'Why are you still in the race?' MORE's 2016 campaign came from voters in the Midwest who previously backed former President Obama but switched over to President TrumpDonald John TrumpTrump fires intelligence community inspector general who flagged Ukraine whistleblower complaint Trump organization has laid off over 1000 employees due to pandemic: report Trump invokes Defense Production Act to prevent export of surgical masks, gloves MORE, progressive strategist Ruy Teixeira said on Wednesday.

"Did she lose because people switched from Obama to Trump? Or did she lose because of a lack of enthusiasm for her candidacy, which resulted in people either not showing up or voting for a third party," Teixeira, author of the "Optimistic Leftist," told Hill.TV's Jamal Simmons on "What America's Thinking."

"This is a debate that has roiled the Democratic Party ever since Hillary Clinton lost the election," he said.

"My sense of the data, looking at a place like Iowa and these other states in the Midwest, is it was primarily a problem of switchers," Teixeira said, adding that "both were important."

Roughly 8.4 million voters who supported Obama in 2012 backed Trump four years later, according to the political website Sabato's Crystal Ball.

Trump in 2016 won historically Democratic stronghold states like Michigan, Wisconsin and Pennsylvania after making multiple trips to the states in an effort to appeal to working-class voters.

— Julia Manchester