2.7 million Californians still don't have health insurance. Can that number go lower?

After a streak of steady declines, California's uninsured rate bottomed out last year with some 2.7 million people still without health insurance.

The last estimates from the U.S. Census offer a fragmented portrait of the remaining people who are uninsured while posing an even bigger question for the state: How much lower can the uninsured rate go?

According to the Census Bureau, 7.2 percent of Californians were without health insurance in 2017. That's lower than the national average of 8.7%

As open enrollment begins this week, health care experts say it will be difficult for the state to move forward, largely because of California's population of immigrants who don't qualify for Affordable Care Act plans. Shana Alex-Charles, a health policy professor at California State University, Fullerton, said about 60 percent of Claifornia's uninsured are hampered by their immigration status.