Hillary Clinton still has a lead against Bernie Sanders in California, but the Golden State has all the right conditions for another upset. A loss next Tuesday would hinder Clinton’s efforts to unify the party and add more potential ruckus to the Democratic National Convention in July.

Vince Vasquez, a senior policy analyst at the National University System Institute for Policy Research, told ABC News that “there’s a good chance for a Sanders upset” in California.

“We may actually be witnessing the same electoral conditions here that occurred in Michigan, where Sanders had a surprise victory on election night, mostly due to spotty polling, pollsters underestimating the millennial vote and Hillary Clinton underestimating the appeal of Sanders.”

According to Bloomberg, the polls have a worse reputation than they generally deserve. In this year’s primaries, the pollsters have been right about 86 percent of the time – which falls short of the 95 percent they typically aim for, but still they clearly have insight. The two battles where the polls were way off this year were Iowa and Michigan.

Bernie Sanders unexpectedly strong campaign has been driven by young people and independent voters. [Photo by David McNew/Getty Images]

As previously reported by the Inquisitr, Michigan went to Bernie Sanders despite him trailing 20 points before the voting. The win was such a surprise that Sanders had not even prepared a speech.

FiveThirtyEight called it the biggest upset since 1984, but could California be even bigger? California’s primary is semi-closed, meaning that independents can vote so long as they registered as “no party preference.” That will be potentially helpful; Bernie Sanders has consistently beaten Clinton among independent voters. Ring of Fire also reports that voter registration in the Golden State is up 218 percent from 2012.

That’s a good sign for Sanders too, assuming those new voters are young people who also tend to vote for the Vermont Senator. The surge in new registrants is a bad sign for pollsters too, because it could throw off the demographic of their likely voter pools.

Still, Real Clear Politics aggregated polls shows that Clinton is still ahead by 8.7 percent. The polls have huge differences between organizations though. KABC/SurveyUSA has Clinton up by 18 points, but PPIC reduces that lead to just 2 percent. The last poll was from May 22.

Then there’s been Bernie Sanders’ extraordinary efforts to persuade California in recent days. His campaign touts that the candidate has spoken to 130,000 people at his 20 rallies and other events so far. His goal is to reach 250,000 people before the primary, meaning that there’s little chance of him relaxing anytime soon.

Sanders explained his grass-roots strategy on Monday in Oakland.

“I’m not sure that has been done in recent history, and the reason we’re doing that is I believe in grass-roots politics. I believe that the people in California and other places have the right to see the candidate up front, ask questions with a lot of town meetings as well and find out where he or she is coming from.”

Elizabeth Warren still isnt ready to formally endorse Clinton, but she is upping her attacks on Donald Trump. [Photo by Chip Somodevilla/Getty Images]

One of Hillary Clinton’s super PACs, Correct the Record, has been sending workers with cameras to keep tabs on Sanders, and the media has been keeping track as well, according to Vasquez.

“Sanders has been campaigning aggressively here in California with large public rallies. That’s kept him in the local news cycle and generated millions of dollars’ worth of earned media.”

In the meantime, Clinton recently picked up a surprise endorsement in California: Governor Jerry Brown. According to the Washington Post, Brown’s criticism of the Clinton’s stemmed all the way back to 1992, when he called Bill Clinton the “Prince of Sleaze” and accused him of “funneling money to his wife’s law firm for state business.”

The fact that Brown has changed his mind is an indication that the party is getting desperate to unify behind Clinton before Donald Trump gets any stronger in the polls, despite Bernie Sanders continued fight.

[Photo by David McNew/Getty Images]