WASHINGTON-- Former Obama administration officials are undertaking a private campaign to encourage people to sign up for coverage next year under the Affordable Care Act.

With the start of open enrollment on Nov. 1, the Trump administration has slashed the Obama health law's ad budget, as well as grants to outside organizations that are supposed to help people sign up. Although Republican attempts to repeal the law have proven futile so far, President Donald Trump hasn't changed his view that the program is a "disaster."

The former Obama officials said their campaign, set to begin Wednesday, will focus on young adults and try to encourage people to sign up for government-backed private health insurance because of subsidies available to cushion the impact of rising premiums.

The effort is headed by Lori Lodes and Joshua Peck, who directed outreach and sign-up efforts during much of former President Barack Obama's second term. Joining them are Andy Slavitt, who ran federal health insurance programs for Obama, activist-actors Alyssa Milano and Bradley Whitford, social commentator Van Jones and insurance industry veteran Mario Molina.

Lodes said the campaign has a modest budget for now, meaning that targeted internet advertising is probably all it can manage, at least initially.

About 10 million people are signed up for subsidized private insurance plans through HealthCare.gov and state-run insurance markets. That figure is well below projections when the law was passed in 2010. An additional 11 million or so have signed up for Medicaid in states that took advantage of the law's expansion of the program to serve more low-income adults.

Under Trump, the open enrollment period for 2018 has been shortened by about half. It now runs through Dec. 15. That's the last day when people can sign up to get coverage that will be effective on Jan. 1.

Some Democrats say that's another indication that Trump is trying to "sabotage" insurance markets. But health insurers, with a vested interest in enrolling people, say a shorter, focused sign-up season period may actually be more manageable.

Returning customers will be automatically re-enrolled unless they shop around and pick another plan.

Health care consultant Dan Mendelson, president of data-tracker Avalere Health, said in an interview that he expects enrollment will remain relatively stable.

"If you think about it, most of the people who are enrolled need the insurance," he said. "They are heavily subsidized and they are going to show up because they need insurance for themselves and their families. I think there will be a base stability to enrollment, but I wouldn't be looking for any major expansion."

Sens. Lamar Alexander, R-Tenn., and Patty Murray, D-Wash., are trying to negotiate a limited bipartisan deal to stabilize state-level markets for individual health insurance policies. People covered under the health law represent about half of those who purchase individual policies.