For the first time, Elizabeth Warren is within the margin of error of Joe Biden in Nevada.

Warren gets high grades, Biden low ones for the last Democratic debate.

Nearly six in 10 say they still might change their minds before the caucuses.

Elizabeth Warren has pulled within striking distance of Joe Biden for the lead in Nevada's influential presidential caucuses.

A new Suffolk University/USA TODAY Network Poll, taken after this month's Democratic debate, shows Biden at 23% and Warren at 19% in Nevada, the state that follows Iowa and New Hampshire in the opening presidential contests next year. Bernie Sanders is at 14%.

While Warren trailed Biden, the Massachusetts senator was within the margin of error of the former vice president for the first time in a public poll in the Silver State.

It is the second poll in recent days to show her gaining on Biden in a key state: She also has surged in Iowa, edging ahead of Biden in a Des Moines Register/CNN/Mediacom Iowa Poll released over the weekend.

"Nevada was Elizabeth Warren's weakest early state but this finding is validation that Warren has reached an important inflection point," said David Paleologos, director of the Suffolk Political Research Center. "The Democratic nomination could now become a two-person race between Warren and Joe Biden, as she is positioning herself for a first or second place finish in the first three Democratic contests."

Among the second tier of candidates in Nevada, California Sen. Kamala Harris was at 4% and South Bend (Ind.) Mayor Pete Buttigieg, entrepreneur Andrew Yang and activist Tom Steyer at 3%.

The poll of 500 likely Democratic caucus-goers, taken by landline and cell phone Sept. 19-23, has a margin of error of 4.4 percentage points.

Issues in Nevada::Poll respondents said top issues are health care, climate change.

'I don't do polls'

The race remains fluid. Nearly six in 10 of those surveyed, 58%, said they might change their mind before the caucuses, scheduled for February. Just 37% said their minds were "firmly made up."

The survey showed Warren positioned to increase her support as the Democratic field narrows. She was the "second choice" of 19%, compared to 16% for Biden, 12% for Sanders and 10% for California Sen. Kamala Harris.

Warren insists it's too early to pay much attention to polls. "I don't do polls," she told reporters when asked about the Iowa Poll. "We are still months away from the Iowa caucuses and the first primary election."

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In national polls, Biden continues to have a durable lead among Democratic voters, now at 30% in the RealClearPolitics average of September surveys. Warren has moved into second place, at 19%, three points ahead of Sanders. In New Hampshire, which holds the first presidential primary, the top three contenders are bunched within a few points of one another. Biden continues to have a yawning lead in South Carolina, which holds its contest a week after Nevada.

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Electability vs. ideology

Nevada Democrats, like those across the country, care more about electability than ideology. By 20 points, 58%-38%, they said the most important thing for Democrats was to nominate a candidate who can defeat President Trump, rather than a candidate "who reflects my priorities and values."

Warren was boosted by her performance in the Democratic debate this month, the third of the series. Among those who watched the forum, she was the candidate most often cited as one who did better than they expected, by 23%. Biden was the candidate most often cited as one who did worse than they expected, at 22%.

That could raise the stakes for both candidates in the next debate, slated for Oct. 15 and 16 on the campus of Otterbein University near Columbus, Ohio. And the spate of good news for Warren could carry a cost: Her rise could well make her the target for her Democratic rivals on stage.