President Trump holds a slim lead in Iowa over former Vice President Joe Biden and Sen. Elizabeth Warren (D-Mass.) in hypothetical match-ups, according to a new poll.

The survey by Emerson College found that 51 percent of registered voters said they would choose Trump over Biden. Respondents favored Trump by the same 51 percent-49 percent margin in a match-up against Warren.

The reverse was the case for Sen. Bernie Sanders (I-Vt.). Fifty-one percent of voters said they would pick him over Trump, who garnered 49 percent support.

The results of all three match-ups fell within the poll's 3.2 percentage-point margin of error.

The survey also found Warren and Biden leading the Democratic field, tied at 23 percent support among Democratic caucusgoers. South Bend, Ind., Mayor Pete Buttigieg was in third place with 16 percent, followed by 13 percent for Sanders.

Researchers surveyed 888 registered voters, including 317 Democratic caucusgoers, from Oct. 13-16. The Democratic caucusgoer responses have a margin of error of plus or minus 5.5. percentage points.

The Iowa caucus is scheduled for Feb. 3.