Michelle Obama would be tied with Biden as frontrunner if she ran in 2020, poll shows

Former first lady Michelle ObamaMichelle LeVaughn Robinson ObamaResistance or unhinged behavior? Partisan hatred reaches Trump's family Budowsky: A Biden-Michelle Obama ticket in 2020? Bloomberg threatens to shake up 2020 primary MORE tied with former Vice President Joe BidenJoe BidenBudget official says he didn't know why military aid was delayed: report Growing 2020 field underscores Democratic divide READ: Foreign service officer Jennifer Williams' closed-door testimony from the House impeachment inquiry MORE as the top choice among Democratic voters when asked who should be the party's nominee in 2020.

A Hill-HarrisX poll released Tuesday found that 25 percent of Democrats said they would back Obama in the party primary over nine other declared or potential candidates, including Sens. Bernie SandersBernie SandersSinger Neil Young says that America's presidents haven't done enough address climate change New poll catapults Buttigieg to frontrunner position in Iowa Growing 2020 field underscores Democratic divide MORE (I-Vt.), Kamala HarrisKamala Devi HarrisNew poll catapults Buttigieg to frontrunner position in Iowa Growing 2020 field underscores Democratic divide Harris gets key union endorsement amid polling plateau MORE (D-Calif.), Elizabeth WarrenElizabeth Ann WarrenNew poll catapults Buttigieg to frontrunner position in Iowa Bloomberg, Patrick take different approaches after late entries into primary race Deval Patrick: a short runway, but potential to get airborne MORE (D-Mass.), and former Rep. Beto O’Rourke (D-Texas).

Obama has said she is not running, and Biden has not announced whether he will launch another White House bid.

Harris came in third among Democratic voters, with 12 percent saying they would support her. Sanders was a close fourth, at 11 percent. O’Rourke, former New York City Mayor Michael Bloomberg, Warren, and Sens. Cory BookerCory Anthony BookerNew poll catapults Buttigieg to frontrunner position in Iowa Deval Patrick: a short runway, but potential to get airborne Overnight Health Care: Warren promises gradual move to 'Medicare for All' | Rivals dismiss Warren plan for first 100 days | White House unveils rules on disclosing hospital prices | Planned Parenthood wins case against anti-abortion group MORE (D-N.J.), Amy KlobucharAmy Jean KlobucharNew poll catapults Buttigieg to frontrunner position in Iowa Election 2020: Why I'm watching Amy and Andy 2020 Democrats demand action on guns after Santa Clarita shooting MORE (D-Minn.) and Sherrod BrownSherrod Campbell BrownOn The Money: Trump asks Supreme Court to block Dem subpoena for financial records | Kudlow 'very optimistic' for new NAFTA deal | House passes Ex-Im Bank bill opposed by Trump, McConnell Warren, Brown press IRS on study reviewing Free File program Sunday shows — New impeachment phase dominates MORE (D-Ohio) all failed to exceed 6 percent.

Biden and Obama garnered 23 percent and 22 percent, respectively, when factoring in independent voters, who are allowed to vote in many state primary elections.

When combining Democratic and independent voters, Sanders received 12 percent, followed by 8 percent for Harris.

Molly Murphy, a partner at Democratic consulting firm ALG Research, said Obama's popularity is helped in large part because she has never thrown her hat into the ring.

"Because she's never been a candidate, she's never been on the ballot, she's avoided a certain degree of scrutiny that candidates face. And so she's all icing for people, it's all good," Murphy said Tuesday on "What America's Thinking," Hill.TV's show about public opinion and polling.

In the Hill-HarrisX poll, 12 percent of independents and Democrats combined said they preferred another candidate, beyond the choices that were offered, suggesting some dissatisfaction among non-Republican voters with the field of declared and potential candidates.

A November Hill-HarrisX poll found that 14 percent of Democratic respondents picked "none of the above" when asked to choose between Warren, Biden, Sanders, Booker, Harris, Bloomberg and former Democratic presidential nominee Hillary ClintonHillary Diane Rodham ClintonGOP divided over impeachment trial strategy 'Too Far Left' hashtag trends on Twitter Resistance or unhinged behavior? Partisan hatred reaches Trump's family MORE.

Obama's surprise appearance at the Grammy awards this month promoted some speculation about a possible 2020 bid. In December, the former first lady said that she had "never" considered a political career and that she had no intention of running for office.

The Hill-HarrisX survey was conducted Feb. 17-18 among a nationally representative sample of registered voters. The overall survey has a sampling margin of error of 3 percentage points.

The group of Democratic respondents has a sampling margin of error of 5 percentage points, and the Democratic and independent set has a sampling margin of error of 4 percentage points.

—Matthew Sheffield