Sen. Elizabeth Warren: No 'Timeline' on Presidential Endorsement

Warren has supported elements of both Democratic candidates' campaigns.

"The way I see it, Democrats are doing exactly what we should be doing," she told NECN in an interview. "I feel an enormous responsibility to make it clear what Democrats stand for."

"We've got to make this fundamentally about the issues," she continued when asked about Clinton's popularity. "It's not about our differences."

"This is what Trump has been fostering and fomenting for months now," she said.