In 2016, Marin County came tantalizingly close to approving a parcel tax that would have raised millions of dollars to support early childhood education. A decade later, with federal budget cuts looming, advocates are trying again.

The threshold for approval is lower this time, thanks to a series of court rulings that allow citizen-initiated ballot measures to pass with a simple majority rather than the two-thirds approval the 2016 measure required.

The initiative would raise $13 million a year for 15 years through a tax of 5 cents per square foot. The annual bill would average about $105 per homeowner.

Advocates for the measure say the need for funding has never been higher, with the Trump administration attempting to withhold early childhood education funds that the county has been counting on—and threatening to slash more.

“There is a serious need for an investment in supporting families to pay for childcare,” said Aideen Gaidmore, chief executive of the Marin Child Care Council. “We have 650 children on our waitlist in Marin for childcare vouchers right now, so we know the need is there. These families need childcare to be able to work and contribute to our economy.”

The money generated by the tax would be used to provide scholarships, boost the pay of childcare workers, and develop, maintain and expand early care and education facilities. Organizers need 15,000 signatures to get the initiative on the ballot; they plan to begin collecting them as soon as the petitions return from the printer. 

The measure is modeled after a similar initiative that Sonoma County voters approved last year. Contra Costa, Alameda and San Francisco Counties have measures on the books that provide dedicated funding to support early childhood education.

In Marin, the annual cost of full-time childcare is a whopping $28,000. Meanwhile, families receiving childcare subsidies through the council have an average income of $39,000 a year.

Money for scholarships, also referred to as vouchers, comes through a complex web of federal and state funding that is sometimes supplemented by funding from private foundations.

The loss of any federal funding would compound the financial challenges at Papermill Creek Children’s Corner in Point Reyes Station. At the end of the school year, it will lose six scholarships, paid for by the Marin Community Foundation, which has realigned its spending priorities.

“Not having scholarship funding is very challenging. It’s devastating for our families,” said Lourdes Romo, Papermill’s executive director.

At Papermill, two thirds of the students receive financial aid. The school is working on a three-year strategic plan to establish a development fund to close the gap left when the foundation changed its priorities.

“Those scholarships end in June, and we have nothing to replace them with,” Ms. Romo said. “We had an open house a few weeks ago, and I had to tell three families who had been on the waiting list that we don’t have scholarships to support them. It’s hard. Very hard.”

The scholarships were administered by the Marin Child Care Council, a nonprofit that is the main resource and referral agency for childcare in the county. The council administers scholarships to 900 low- and middle-income families and has a waiting list of 650 more.

Besides providing scholarships, the parcel tax initiative aims to improve the salaries of childcare workers, who earn an average of $23.50 an hour. With expenses in Marin so high, attracting and retaining staff is extremely difficult.

“The biggest challenge in this business is staffing,” said Dave Cort, vice president of the board at the San Geronimo Childcare Center. “A major priority for our board is to be able to increase pay and benefits.”

The 2016 initiative, which earned 63 percent of voter support, was championed by Matt Willis, then Marin’s public health officer, and Mary Jane Burke, then the superintendent of the Marin County Office of Education. They are also supporting the current campaign, applying lessons learned from their previous effort.

“The first five years are by far the most rapid and foundational periods of our brain development,” Dr. Willis said. “By the time we get to kindergarten, so much of that architecture has already been laid. If we wait until kindergarten to begin to focus on nourishing young brains to learn, we’ve already missed the most important years.”

The campaign is led by a political action committee called Our Kids, Our Future. “The timing for this is right, and we have lots of momentum,” said Joanne Webster, the committee chair. “We have convened a very educated and enthusiastic group to help us get this across the finish line.”

Ms. Webster is president of the North Bay Leadership Council and a former president of the Marin Chamber of Commerce.

“Childcare, and especially accessibility to affordable childcare for working families, has been identified by employers as a really important priority,” she said.

Under Gov. Gavin Newsom, the state implemented universal transitional kindergarten programs at all California public schools. But those programs, which serve students age 4 and up, don’t always meet the needs of working families with unpredictable schedules, Ms. Webster said.

“If you have to be at work at 6:30 in the morning, and you have an hourlong commute, the TK program doesn’t help you, because your kid has to be at school at 8 a.m.,” she said. “It’s not flexible—it doesn’t do nights and weekends and super early mornings—and so it doesn’t benefit everyone.”

Many smaller daycare centers and private preschools that meet the needs of those families have closed or struggled in recent years as families have left them for public TK programs, she said. In addition to providing scholarships, proceeds from the parcel tax could be used to support private operations that fill the gaps.

“No one should have to choose between making a wage and taking care of their kids,” Dr. Willis said. “Early childhood education sets the stage for so much of what we see later in life, in terms of educational attainment, in terms of income, even in terms of health.”