Ask Elizabeth Warren if she is the best candidate to beat Donald Trump, and her response is immediate: "Yes, I am," she said. "I know how to fight and I know how to win."

Yet recent polls and her latest fundraising indicate not all Democrats are as confident.

"Despite her populist message, she's not resonating yet among working class white voters in New Hampshire," said University of New Hampshire Professor Dante Scala.

Combine that with the rise of Pete Buttigieg among white, college-educated voters, and Scala says Warren has her work cut out for her, especially if she plans on becoming the top choice for progressives.

"It's pretty clear that Bernie Sanders isn't going anywhere," Scala said.

Sanders has just reported a record $35 million haul in the past quarter.

Warren insists she is not concerned and says she will release her numbers soon.

"I didn't spend one single minute selling access to my time to millionaires and billionaires," she said. "I did this grassroots."

Warren's dip can be traced to the release of her plan for how she would pay for "Medicare for All" -- an issue she has reportedly talked less about on the campaign trail in recent weeks.

Asked if that was a conscious decision based on poll numbers or fundraising, Warren said, "I take questions. And I go wherever the questions take me. I only do a short piece at the top and I go wherever the voters want to go. And that's what I've been doing for a long time now."

Middlebury college professor Matthew Dickinson says Warren is still well-positioned.

"I wouldn't overreact to it," Dickinson said. "It doesn't mean she's on her last legs. She certainly raised a lot of money."

Warren also touched on the issue of her electability.

"I remember when Barack Obama was 'not electable.' I also remember when Donald Trump was 'not electable.' But I also remember what they got out and talked to people about. And that is big change," she said.

Asked if she does not win, will she wholeheartedly get behind the Democratic nominee, Warren said yes, she is all in, adding that this time, the Democrats need to win not by a slim margin, but with a major electoral victory.