As the past week saw Warren almost neck and neck with frontrunner Joe Biden in the polls, Democratic strategist and communications expert Michael Gordon told Newsweek that Warren’s enthusiasm and campaign, combined with a problematic time for Biden, currently give her the edge.

“In the Republican Primaries, Trump was ahead. He was in the same position Biden has been in. People didn’t think voters would support him but they did—and he had the kind of enthusiasm that Warren is seeing now,” Gordon said.

“I think what’s happening with Biden is there’s just starting to appear a cumulative effect of his gaps and other controversies such as this one,” he added of the Ukraine whistleblower allegations that Trump asked Ukrainian President Volodymyr Zelensky to investigate potential political rival Biden.

In a phone call, the summary of which was shared by the White House last week, Trump said to Zelensky: “There’s a lot of talk about Biden’s son, that Biden stopped the prosecution and a lot of people want to find out about that so whatever you can do with the Attorney General would be great. Biden went around bragging that he stopped the prosecution so if you can look into it… It sounds horrible to me,” he added.

And as Biden’s name has continued to come up, with Trump and his personal lawyer Rudy Giuliani insisting he should be investigated, Warren has seen a surge in the polls—but Gordon said the Ukraine allegations were not the only cause.

“Some of that is built into his (Biden’s) numbers already but with Warren surging, there is now a clear alternative and Biden is not the impenetrable frontrunner that he was even a month ago,” Gordon continued. “And there’s also a clear enthusiasm gap percolating between the two. I always put my money on the candidates with the most enthusiasm, and that’s Warren right now.”

“I think this current issue will be a factor, but in part, because it’s part of a larger narrative of Biden being an imperfect candidate,” Gordon said.

Figures from Quinnipiac University Poll and Emerson College Poll show Warren closing in on Biden.

“Warren is surging and she is going to continue to surge so we are just seeing the beginning of it, and that very much has to do with the substance of her campaign as well as her debate performance,” Gordon said. “She has also had some good talk show appearances and things like that, so it’s the whole of everything that has worked in her favor. It’s a combination of those things and it’s a credit to her campaign as well as her winning what I call the media primary early on. Her name recognition was pretty high going into this cycle.”

While Gordon dismissed the idea of an outside candidate making a surprise bid for victory as the campaigns continue, he did rate California’s Kamala Harris and New Jersey’s Cory Booker, who he suggested could be Warren’s running mate.

“He has never broken into the top tier [of Democratic hopefuls] but it strikes me that he’d be an excellent president, and if he doesn’t win the nomination he’d be an excellent running mate,” Gordon said.