Bernie Sanders has narrowed the gap with Democratic frontrunner Hillary Clinton in California, bringing the presidential primary race into the margin of error, according to a poll released late Wednesday.

The poll by the Public Policy Institute of California shows Clinton leading by just two percent, 46-44. That’s within the margin of error, and a big increase for Sanders over a March poll by the same company that showed Clinton with a 48-41 percent lead.

The poll comes as both candidates have ramped up their efforts in the Golden State ahead of the June 7 contest, and as Clinton has been dogged by a potentially damaging State Department inspector general report on her use of a private email server.

The report concluded that the former secretary of state’s use of private email for State Department business was “not a casual oversight” and that she ignored repeated warnings to use official communications.

The poll found that Clinton has a slight lead over Sanders among registered Democrats, 49-41 percent, suggesting a significant segment of Sanders’ support comes from independents.

The poll contradicted a SurveyUSA poll released Monday that showed Clinton with a formidable lead over the self-described democratic-socialist, giving her a 57-39 percent lead.

That poll showed significant differences among different age groups. While Sanders leads among younger voters, Clinton leads by 12 points among voters 35-49, by 34 points among voters age 50-64 and 45 points among voters 65 and over.

While a defeat in California would almost certainly not stop Clinton from gaining enough delegates to clinch the nomination, it would damage the narrative of her as the presumptive nominee and would encourage Sanders to remain in the race until the convention in July.