Democratic presidential candidate Sen. Kamala Harris released a health care plan on Monday that would put the US on the path toward a government-backed health insurance system but stops short of completely eliminating private insurance.

Harris' proposal, which her campaign unveiled just days before she takes the stage in Detroit for the second Democratic presidential debate, hosted by CNN, positions her to the right of progressives, such as Sen. Bernie Sanders, whose plan goes farther and gets to a "Medicare for All" health care system more quickly. But it is to the left of moderates like former Vice President Joe Biden, who would retain the present system but add a government-run -- and presumably less expensive -- insurance option to the Affordable Care Act exchanges.

The future of private insurance in America has become a key point of difference among the more than 20 candidates running for the 2020 Democratic nomination and a litmus test among progressives who have publicly declared their support for "Medicare for All." Harris has offered mixed messages so far on the role of private insurance, at times indicating she'd eliminate private coverage and at other points saying that she'd keep it in some form.

Her plan makes clear she supports a role for private insurance companies within the health care system, in a stark difference from the Medicare for All Act proposed by Sanders, which essentially eliminates private insurance. Harris calls for transitioning to a Medicare for All-type system over a 10-year period -- longer than the four-year transition period laid out by Sanders. Her plan also does not raise middle class taxes, another distinction with Sanders.