Twenty-four percent of Iowa's likely Democratic caucusgoers say former vice president Biden is their first choice for president.
Mr Sanders, a United States senator, is the first choice for 16 percent of respondents, while Ms Warren, also a USA senator, and Mr Buttigieg, the mayor of South Bend, Indiana, are at 15 percent and 14 percent, respectively. Kamala Harris comes closest at 7%, and other numbers within the poll indicate some underlying strengths for her.
Biden says in remarks prepared for delivery on Tuesday that Trump "thinks he's being tough" and "it's easy to be tough when someone else is feeling the pain".
Spotlighting the anxiety he said farmers are feeling, Biden will ask "how many have had to stare at the ceiling at night wondering how they're going to make it?" That was part of his effort to emphasize the economy- an issue the president often promotes as his chief strength in a time of low unemployment - during a speech in Davenport, a center of eastern Iowa's agricultural manufacturing industry.
Overall, President Trump had a 13 percent approval rating in the survey, compared to 82 percent who said they disapprove of the job Mr. Trump is doing.
Therefore, it is not surprising that Biden's lead is more commanding in "national" polls than what one finds in Iowa.
Early polling from several outlets shows Biden easily besting Trump.
Dallas Keuchel, Braves agree deal
He went 12-11 with a 3.74 ERA and 153 strikeouts last season for Houston and then started two playoff games and posted a 3.60 ERA. Until Monday, teams signing either Kimbrel or Keuchel would have lost a draft pick because they turned down qualifying offers.
Minutes later, Biden used a speech in Iowa to describe Trump as "an existential threat to America".
"It's good that he is coming back", Iowa State Rep. Lisa Heddens said, according to CNBC. Reagan, of course, went on to win both the nomination and the general election that fall over Jimmy Carter. Iowa holds the first Democratic nominating contest next February.
But Democratic candidates in their 40s and 50s - and even 37-year-old Pete Buttigieg - could yet seize the momentum and make their youth an issue in a country where many Democrats yearn for radical change.
In a field of inauthentic candidates trying to be authentic, Biden's statement cuts through.