Buttigieg leapt from 11 percent in the Monday poll of New Hampshire voters to 15 percent Tuesday, putting him neck-and-neck with Biden.

Sanders, who handily defeated Hillary Clinton in New Hampshire four years ago, held steady at 24 percent in the second of seven daily tracking surveys, while Biden dropped from 18 to 15 percent.

Former vice president Joe Biden has dropped further behind Senator Bernie Sanders in New Hampshire, while former South Bend, Ind., mayor Pete Buttigieg is seeing a bump in support that may reflect his strong showing in Iowa, according to a new Boston Globe/WBZ-TV/Suffolk University poll of likely Democratic primary voters.


Senator Elizabeth Warren of Massachusetts received 10 percent of support in the new poll, down from 13 percent a day before. All other candidates were in the single digits, and 13 percent of voters were undecided.

The always-important New Hampshire presidential primary, now less than a week away, is poised to take on additional significance this campaign cycle as the Iowa Democratic Party slowly releases results from its chaotic caucuses on Monday, leaving a cloud of confusion over the results.

“Sanders improved a little bit, but he basically flatlined, and I think that’s partly due to the fact that he was expected to win Iowa,” said David Paleologos, director of the Suffolk University Political Research Center, which is conducting the series of polls.

Sanders appeared to have placed second in Iowa, behind Buttigieg, as of Tuesday night, with 62 percent of the state reporting.

With the declining poll numbers and a potential fourth-place showing in Iowa, based on early results, Biden appears potentially vulnerable after months as the front-runner in national polls. And Buttigieg may be surging.

“This could be just a temporary spike — it could be what we call a head fake,” Paleologos said of Buttigieg’s poll numbers. “Or it could be a continuing trend.”


The results of the next round of polling, to be released Wednesday night, will help show whether Biden’s loss and Buttigieg’s gain are mere blips, he said.

The poll results were released just moments after President Trump completed his annual State of the Union address, and less than 24 hours ahead of a scheduled vote in which Trump is likely to be acquitted in his Senate impeachment trial.

Despite harsh criticism by Democrats, strong testimony against him, and his impeachment in the House of Representatives, Trump has reached his highest-ever job approval rating — 49 percent, according to a Gallup poll released Tuesday ahead of Trump’s speech.

In the Republican Iowa caucuses, Trump won by 97 percent. Former Massachusetts governor William F. Weld garnered only 424 votes, or 1.3 percent.

Tuesday’s poll, conducted by Suffolk’s Political Research Center on Monday and Tuesday, is the second of seven daily tracking surveys that will be released ahead of the New Hampshire primary.

The polls reflect a two-day rolling average of 500 likely voters, with 250 interviews conducted by live callers surveying people on landlines and cell phones each night. Each poll has a margin of error of plus or minus 4.4 percentage points.

Jeremy C. Fox can be reached at jeremy.fox@globe.com. Follow him on Twitter @jeremycfox.