The evidence so far suggests they won’t. The administration recently ended $23 million worth of contracts with two companies that helped people sign up for coverage. It also is cutting the enrollment period in half in most states, to 45 days. A number of advocacy groups that worked closely with the Obama administration to get the word out about open enrollment have heard nothing from the Trump administration about re-upping the partnerships this year.

All of this has Ms. Barker and other Obamacare enrollment counselors around the nation, many of whom rely on federal grants to carry out their work and to keep their jobs, revving up earlier than usual, and bracing for the strange new challenge of promoting coverage that the president is attacking at the same time. They are not even certain the law’s mandate that most Americans have health insurance or pay a tax penalty will be enforced.

A recent sticky Friday found Ms. Barker passing out fliers about open enrollment at a back-to-school fair in East Nashville. To every parent and grandparent who strolled past, she asked, “You have health insurance?” Nearby was her favorite prop: a wheel that passers-by could spin with a dial that landed on terms like “deductible” and “penalty,” which she cheerfully explained to those willing to listen.

For the law’s first four enrollment seasons, the Obama administration spent heavily on advertising, recruited celebrities like Katy Perry and companies like Uber to spread the word and scrutinized data to pinpoint potential customers. But this year, community-based enrollment groups, known as navigators, may be largely on their own.

“This is going to be the heaviest lift we have ever tried to undertake,” said Jessie Menkens, navigator program coordinator for the Alaska Primary Care Association. “We will be shouting out for people to recognize this really is not over — that regardless of what deliberations are happening in Washington, this is still truly the law of the land.“