How much sway do past Democratic nominees have? Unless you're Barack Obama, not much.

Show Caption Hide Caption Difference between caucus and primary, explained The 2020 election is nearing and with that, comes the caucuses and primary elections. But what’s the difference?

Once they won the Democratic presidential nomination. But do their endorsements matter now?

Unless your name is Barack Obama, not really.

A national USA TODAY/Suffolk Poll asked likely Democratic voters whom among the party's past presidential nominees would have the most influence on their vote today. Two-thirds named former president Obama, who moved out of the White House almost three years ago.

Obama hasn't endorsed anyone so far, including his former vice president, Joe Biden.

Kate Pritchard, 63, a retired teacher from Durango, Colorado, is supporting New Jersey Sen. Cory Booker at the moment, but she's not sure he can go the distance.

If Obama were to endorse a candidate, she would back that person.

"That would be very powerful," she said in a follow-up interview after being called in the survey.

In the poll, 11% cited former president Jimmy Carter, who at age 95 is still building houses and doing other good works, as influential with them. But all the other former nominees registered in single digits.

The only other nominee to win the White House, Bill Clinton, was named by just 6%. Hillary Clinton, the party's standardbearer the last time around, also was cited by 6%. Al Gore, the 2000 nominee, was named by 3%, and Michael Dukakis (1988), John Kerry (2004) and Walter Mondale (1984) by 1% each.

Asked whom would have the least influence on their vote, Dukakis ranked first, at 23%, and Hillary Clinton was second, at 18%.

USA TODAY/Suffolk Poll: Biden's lead narrows in turbulent Democratic field

Hillary Clinton created a firestorm last week when she called one of the 2020 contenders, Hawaii Rep. Tulsi Gabbard, "a favorite of the Russians." That brought denials from Gabbard and a divided judgment by Democratic voters.

In the poll, 46% said Hillary Clinton should continue to speak out about issues important to her. Precisely the same number, 46%, said she shouldn't inject herself into the 2020 election.

The poll of 399 likely Democratic primary and caucus voters, taken by phone from Oct. 23-26, has a margin of error of plus or minus 4.9 percentage points.

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