Joe Biden may be leading national polls among Democratic voters, but a new poll shows his dominance doesn’t necessarily extend to Iowa.

Mr Biden is matched by Bernie Sanders in the state, a sharp drop from his 11 point lead in a separate poll last month. Both candidates can claim 24 per cent support in the state, which will vote first in the nominating process next year.

Mr Biden and Mr Sanders are followed in the new poll by several candidates with significant showings, including Pete Buttigieg (14 per cent), Elizabeth Warren (12 per cent), and Kamala Harris (10 per cent).

Reading into the polls just a bit more, Mr Biden has more to worry about than just Mr Sanders, too.

Ms Warren stands out as the most liked candidate in the race, with a favourability rating at 78 per cent — the top in the race. She is followed by Mr Sanders, who is the next closest with 71 per cent.

“Good news for Elizabeth Warren: her favourability exceeds that of any other candidate in the race and her name recognition is near universal,” said principal pollster Jane Loria in a news release.

She continued: “In some states, we see a large spread between the front-runners and the so-called second-tier in the excitement barometer, but in Iowa the candidates are all pretty tightly clustered. When we ask respondents to identify the five candidates they’re most excited about, 54% say Warren, followed by Biden (53%), then Harris (53%), Sanders (49%), and Buttigieg (46%)

The terrain looks much better for Mr Biden when looking at the other states that follow close after Iowa, however. In New Hampshire, Mr Biden beats Mr Sanders 36 per cent to 18 per cent. In South Carolina, meanwhile, Mr Biden recently got 46 per cent support compared to Mr Sanders’ 15 per cent.

But, any fragility in Iowa could have real consequences for Mr Biden’s third presidential race. The state has an outsized influence on the presidential nominating process, and a loss there would show potentially significant vulnerabilities for the former vice president.

The Iowa Starting Line/Change Research Poll was released on Monday, and the Iowa caucuses will be held in January.