A Democratic candidate for governor is proposing a Medicaid-for-all health care system in Colorado, endorsing a public option at the state level amid the gridlock on health care in Congress.

Cary Kennedy said she wants to allow anyone on the individual market to join the Medicaid system or the state employee health care plan to provide more affordable and high-quality health care options.

The average 27 percent rate hike announced for 2018 is “simply too much,” Kennedy said at a campaign event Tuesday in Denver, “and far too many people in our state are not able to get the care that they need.”

“I am proposing things we can do right here, right now in Colorado without relying on Congress,” Kennedy added.

The former state treasurer’s plan represents an early marker in the crowded 2018 Democratic primary on the issue of health care. And her plan drew quick criticism from one rival, as well as Republicans who want to reduce the size of Medicaid, not expand it.

“It’s another example of making policy positions that have no basis in fact,” said Noel Ginsburg, a Democratic rival and businessman. “If, in fact, we could lower premiums by 20 percent, we would have done it already.”

Under Kennedy’s plan, anyone who joins the state Medicaid system, known as Health First Colorado, would pay the full cost of their coverage with premiums. Right now, the state-federal program mostly covers health care costs for lower-income residents, as well as children and the disabled.

Kennedy could not provide an estimated cost for an individual. But she said with lower administrative costs, no profit motive and a larger insurance pool, Medicaid could provide health coverage for 20 percent less than the private policies on the state’s health care exchange.

The expansion of Medicaid and extension of the state employee health care plan is particularly aimed at rural Colorado, given the elevated rates on the Western Slope and out on the Eastern Plains. In 14 of the state’s 64 counties, only one insurer is offered on the insurance exchanges.

The competition in the marketplace, Kennedy said, would “lower costs for all health care consumers.”