As the legal battle plays out, eight school districts as of Tuesday afternoon had voted to require masks for students, with exceptions only for students whose parents submit doctors’ notes. The mask mandates in the eight counties cover an estimated 1.23 million students, based on state enrollment data from the 2020-2021 school year.

DeSantis issued the order July 30 in an effort to block county school boards from requiring students to wear masks as the delta variant of the coronavirus has caused a surge in COVID-19 cases. The governor contends that parents should be able to decide whether their children wear masks.

But a group of parents filed the lawsuit, alleging that the executive order violates a section of the state Constitution that requires providing a “uniform, efficient, safe, secure and high-quality system” of public schools. Leon County Circuit Judge John Cooper began hearing testimony Monday and is scheduled to finish Wednesday.

The hearing Tuesday kicked off with plaintiffs’ attorneys calling medical doctors as witnesses, with arguments centered mostly on the efficacy of wearing masks to help the spread of COVID-19.

“It keeps me from sharing my germs with you, and it keeps you from sharing your germs with me. So, regardless of whether I’m vaccinated or not or you’re vaccinated or not, it is protecting both of us,” said Mona Mangat, an allergist and immunologist.

The state’s lawyers later called their first witness, Stanford University professor of medicine Jay Bhattacharya, who testified about the “harms” of requiring children to wear masks.

“If you look at the pre-COVID literature, it emphasizes that children need to be able to see faces in order to develop in many, many ways, including social development, emotional development, some evidence on language acquisition. Especially with young children,” Bhattacharya said.

Meanwhile,a growing number of school districts have set mask requirements in opposition to DeSantis’ order and a resulting Department of Health rule that says parents must be able to opt out of mandates.

The Duval County School Board on Monday became the eighth district to approve a mask mandate with only medical reasons allowed as exceptions. It joined Alachua, Broward, Palm Beach, Sarasota, Hillsborough, Miami-Dade and Leon counties.

State Board of Education Chairman Tom Grady and Vice Chairman Ben Gibson signed orders Friday that threatened to withhold district funds in amounts equal to the collective monthly salaries of school board members if districts did not change course. The orders were directed to the Alachua and Broward school districts.

Broward County responded to the state Tuesday, saying the district will not reverse course despite pressure from the state board.