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

Former first lady Michelle ObamaMichelle LeVaughn Robinson ObamaMichelle Obama to headline Essence Festival Obama shares tribute to Michelle to celebrate Mother's Day 111-year-old woman gets free tickets to see Michelle Obama book tour MORE tied with former Vice President Joe BidenJoe Robinette BidenBiden calls for unity, jabs at Trump in campaign launch Here are the potential candidates still eyeing 2020 bids Warren policy ideas show signs of paying off 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 SandersHere are the potential candidates still eyeing 2020 bids Sanders unveils education plan that would ban for-profit charter schools Warren policy ideas show signs of paying off MORE (I-Vt.), Kamala HarrisKamala Devi HarrisHere are the potential candidates still eyeing 2020 bids Warren policy ideas show signs of paying off Hillicon Valley: Florida county that backed Trump was one of two hacked by Russians | Sandberg pushes back on calls to break up Facebook | Conservative groups ask WH to end Amazon talks over Pentagon contract MORE (D-Calif.), Elizabeth WarrenElizabeth Ann WarrenHere are the potential candidates still eyeing 2020 bids Sanders unveils education plan that would ban for-profit charter schools Warren policy ideas show signs of paying off 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 BookerOvernight Health Care — Presented by Campaign for Accountability — Momentum builds for federal laws enshrining abortion rights | Missouri lawmakers approve bill banning abortions at 8 weeks | Warren unveils plan to protect abortion rights 2020 Dem Seth Moulton calls for expanding cannabis access for veterans Momentum builds behind push to pass laws enshrining abortion rights MORE (D-N.J.), Amy KlobucharAmy Jean KlobucharInslee gives public option first test in Washington state Momentum builds behind push to pass laws enshrining abortion rights Poll: Biden is only Dem candidate that beats Trump outside of margin of error MORE (D-Minn.) and Sherrod BrownSherrod Campbell BrownLawmakers grapple with the future of America's workforce The Hill's Morning Report - Presented by Pass USMCA Coalition - Restrictive state abortion laws ignite fiery 2020 debate On The Money: Mnuchin signals officials won't release Trump tax returns | Trump to hold off on auto tariffs | WH nears deal with Mexico, Canada on metal tariffs | GOP fears trade war fallout for farmers | Warren, regulator spar over Wells Fargo 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 ClintonWarren policy ideas show signs of paying off Biden at campaign kickoff event: I don't have to be 'angry' to win Top Dem: Trump helps GOP erase enthusiasm gap; Ohio a big problem 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