Democratic presidential candidate Hillary Clinton speaks at a rally in Newark, N.J. (Spencer Platt/Getty Images)

DAVIS, Calif. — A trio of widely respected polls released this week have found the Democratic primary closing to a 2-point race, with former secretary of state Hillary Clinton's advantage over Sen. Bernie Sanders of Vermont narrowed by her dipping favorable rating and his rising support from independents.

The latest and most closely watched of the three "live caller" polls — i.e., those that rely on human interviewers to get results instead of robocalls — was the Field Poll that dropped Wednesday night. (Polls that use automated callers find a larger Clinton lead.) Among all voters, Clinton led Sanders by a 45-43 margin. Among registered Democrats and the quarter of voters who had cast ballots already, Clinton led by 9 points, by small margins with white and Latino voters, and by a 2-1 margin with black voters.

But Sanders enjoyed a 54-27 lead with "no party preference" voters, who can request a Democratic ballot. By a 20-point margin, his voters described themselves as more enthusiastic than Clinton's supporters. And Sanders, who has kept up a relentless schedule in California, is viewed positively by 76 percent of primary voters; Clinton is viewed favorably by 64 percent.

Polls this week from the Public Policy Institute of California and NBC News/Marist found the same margin, 46-44 and 49-47, respectively. PPIC had found Clinton's lead falling by 5 points since March; for the Field Poll, it was a drop of 4 points.

A narrow loss in California would not halt Clinton's path to the nomination. Based on the Democratic Party's apportionment of delegates, a worst-case scenario for Clinton in June 7's primaries — losses in five of that day's voting states and a victory in New Jersey — would still give her a majority of the party's pledged delegates and keep her advantage with the popular vote. There are just 59 pledged delegates in the Montana, North Dakota and South Dakota contests that Sanders is favored to win; there are 126 available in New Jersey. In the hotly contested 2008 primaries, slightly more than 400,000 votes were cast across those states; more than 1.1 million votes were cast in New Jersey.


Democratic presidential candidate Bernie Sanders waves to supporters in Santa Monica, Calif. (AFP/Getty Images)

Still, to Sanders's unconcealed delight, the Clinton campaign scrapped some of its upcoming New Jersey schedule to send the candidate and former President Bill Clinton back to California, a state neither of them has ever lost. At a morning news conference and today's rallies in Palo Alto and Davis, Sanders boasted he was making the Clintons "nervous" by threatening them with a humiliating loss.

"I'm shocked!" said Sanders on Wednesday morning. "You know why? Because you all told me the campaign was over. I wonder why Secretary Clinton and her husband, Bill, are back in California? I thought it was all over, but maybe Secretary Clinton and her husband are looking at some polling that suggests otherwise."

As he crisscrossed the Bay Area and Capital Region, Sanders brimmed with confidence. He pledged to stump well past June 7, on to Washington's June 14 primary, and in a Wednesday email to D.C.-area supporters the campaign said it needed housing for its coming campaign staff. As the sun set in Davis, Sanders took credit for President Obama's surprise announcement that he favored expanding Social Security benefits, a long-held position of Sanders and progressive activists.

Clinton had less to brag about, but a few things to cling to. In 2008's much earlier California primary, the final Field poll found Clinton's support collapsing from 12 points to 2 points. She won by 9 — and lost the Democratic nomination.