Editor’s Note: Dean Obeidallah, a former attorney, is the host of SiriusXM radio’s daily program “The Dean Obeidallah Show” and a columnist for The Daily Beast. Follow him @DeanObeidallah. The opinions expressed in this commentary are his own. View more opinion articles on CNN.

CNN  — 

Donald Trump has every reason to be concerned about taking on former Vice President Joe Biden in the 2020 election, especially given that a Fox News poll released this week found him trailing Biden by a whopping 14 points if the election were held now. But Trump’s greatest threat may in fact come from Massachusetts Senator Elizabeth Warren, who leads Trump by six points in the poll.

Per a CNN/Des Moines Register/Mediacom poll released Saturday, Warren has for the first time taken the lead among likely caucusgoers in that key first primary state, climbing seven points since June. And Warren appears poised to rise further if other Democrats drop out or falter in the race, given that the poll finds she’s the top second choice among all other Democratic candidates. Twenty percent would choose Warren as a second choice while Biden and Bernie Sanders are each only the second choice of 10%.

Dean Obeidallah

Biden still currently leads Warren in the Real Clear Politics average of polls on a national level by a little over ten points. But Warren has been slowly building support in a way that may not only lead her to win the nomination, but to win the White House come 2020.

Why? It’s simple: Warren is increasingly exciting people about her candidacy. This is backed by a new NBC/WSJ poll released Sunday which finds that among all the 2020 Democratic candidates, she is now the top-tier candidate who the largest amount of registered voters (17%) are “enthusiastic” about. While that number has grown from just 8 percent in March, the percentage of voters who are enthusiastic about Trump has remained the same at 26%. Biden, however, has seen the opposite trend. In March, 17% of voters were enthusiastic about him, but now the former VP has slipped to 12%. That’s not good. Enthusiasm should only be growing the more people see a candidate in debates and on the campaign trail.

True, enthusiasm is an intangible factor that can come and go, often quickly. But it’s enthusiasm that inspires people to not just vote, but to get friends to vote. It’s that passion that animates people to knock on doors for a candidate, make phone calls, give money and attend events.

In fact, just this past week, we saw an example of Warren enthusiasm on display when she held a rally in New York City and some 20,000 people reportedly attended. The massive crowd clearly unnerved Trump, who loves to brag that he draws the largest audiences. When asked about the rally by reporters, Trump did his best to downplay it, saying, “No. 1, she didn’t have 20,000 people and No. 2, I think anybody would get a good crowd there.”

But it wasn’t just the New York City rally, Warren has been increasingly drawing impressive, energetic crowds, such as in August when 15,000 people came to her rally in Seattle and 12,000 attended another rally in St. Paul, Minnesota.

How did Warren climb from single digits in national polls in March to now topping Biden in the new Iowa poll? She hit all the right notes with Democrats and especially with the progressive wing of the party. Her debate performances have been consistently very good. Warren’s ‘I have a plan for that’ mantra where she has released detailed plans for policy issues facing our nation from childcare to anti-corruption to criminal justice reform – and the list goes on – has resonated with voters.

She has also been very outspoken on another issue supported by approximately 70% of Democrats: Impeaching Trump. Warren was the first major presidential candidate to call for impeaching the President back in April, just days after Robert Mueller’s report was released. And on Friday after allegations were reported that Trump spoke to the Ukrainian President in July and pressured him to investigate Biden and Biden’s son Hunter in an obvious effort to get dirt on Biden, Warren went a step further.

She took to Twitter slamming Democrats in Congress for failing to act, writing, “After the Mueller report, Congress had a duty to begin impeachment. By failing to act, Congress is complicit in Trump’s latest attempt to solicit foreign interference to aid him in US elections.” She added, “Do your constitutional duty and impeach the president.”

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    In contrast, Biden’s first response to reporters on the issue was understandably more defensive: “Not one single credible outlet has given credibility to these assertions. Not one single one,” adding, “So I have no comment other than the president should start to be president.” Later that night Biden put out a more forceful statement saying if the allegations are true, it is “clear-cut corruption.”

    However, as someone who speaks to the progressives nightly on my SiriusXM radio show, I can tell you firsthand that Warren’s words and sentiment line up perfectly with the frustration many rank and file Democrats have with the Democrats in Congress on this issue.

    Between now and the 2020 election a great deal can change. But if Warren and Biden continue along their current trajectory, Trump should fear Warren as much, if not more, than Biden.