Bernie Sanders is surging across the Democratic primary landscape, with a series of polls showing him slashing Hillary Clinton’s leads in the critical states ahead and becoming competitive in states where he once appeared to have no chance.

After a come-from-behind victory in Wisconsin, where he turned what was a consistent double-digit deficit early in the campaign season into a 13-point win, Sanders would appear to have the potential for more upsets on the horizon as his momentum continues to cut into Clinton’s leads in New York, Pennsylvania, and Maryland.

In one of the most important developments for Bernie Sanders, a Friday poll showed that he has cut deeply into Clinton’s lead in delegate-rich California with still two months until the primary.

The Field Poll showed that after trailing by double-digit margins in January, Bernie Sanders is now just 6 percentage points behind Hillary Clinton.

“He’s building some momentum,” poll director Mark DiCamillo told the Sacramento Bee.

The poll found that while Clinton still leads by 10 percentage points among independents likely to vote in the May primary, Sanders is dominating the younger demographics. He is up by 25 percentage points among likely voters in their 30s and by an even wider margin among younger voters.

Sanders is also cutting into the Latino vote, once a solid voting block in Clinton’s favor. While Clinton once held 20 or even 30-point leads among Latino voters in earlier states, the gap is now just 7 percentage points in California.

#BernieSanders leads Clinton 63-31 w/ Latinos nationwide, but he can only appeal to white ppl. #HillarySoQualified https://t.co/YQ8yULNR89 — Julia Gumm (@jujubee_84) April 7, 2016

That could be trouble for Hillary Clinton, DiCamillo said.

“Latinos would be a traditionally strong segment for Hillary, she’d have it in her back pocket,” he said, adding that now “it’s one of the segments that’s moving away.”

The Sacramento Bee noted that the strong numbers in California could be a bellwether for Sanders’ ability to compete in other, earlier large states. An important vote looms in New York, where Clinton spent eight years as a United States Senator and still enjoys large support.

But even here Bernie Sanders is surging, taking a Clinton lead that was consistently in the 20s — and even as high as 48 points in one recent poll — and cutting it to 10 percentage points with a little less than two weeks left.

Bernie Sanders is surging even in states seen as friendly to Clinton. Maryland is viewed as one of her safest states remaining, with a high African-American voting bloc that to this point has tilted heavily in her favor. Clinton had consistently held leads in the 30s in Maryland, but a poll this week from the University of Maryland/Washington Post shows that Sanders has cut that in half and is now trailing by just 15 points.

While that still leaves a lot of ground to make up, Bernie Sanders would not need to rely on a win in Maryland to keep on his path to reach Clinton in the delegate count. In an analysis in March from FiveThirtyEight pollster Nate Silver, Sanders’ goal for Maryland was to hold Clinton’s win to just 9 percentage points. So even if Clinton were to win Maryland but by a smaller margin, it could still be a positive development for Sanders.

Despite the challenge ahead, the polls show that Bernie Sanders may be in the strongest position in weeks and could be poised to make it a tight race if he can keep up the momentum of the last few weeks.

[Photo by Scott Olson/Getty Images]