Gov. Doug Ducey explains why he thinks it's OK to attend large political rallies with people not wearing masks even as Cara Christ, his own health director, warns of the risks of spread of COVID-19 at these events.

PHOENIX — Gov. Doug Ducey is defending allowing and attending potential “super spreader’’ political rallies for President Trump — and not wearing a mask — even as he concedes the number of cases of COVID-19 in Arizona will rise and he is urging people to take precautions.

At a press briefing Thursday — the first specifically on the issue of the virus in more than a month — Ducey pointed out that his executive order banning gatherings of more than 50 does not apply to activities protected by the First Amendment. That, he said, includes what the Trump campaign organized even though governors of some other states have imposed and enforce their own bans on such large gatherings.

Ducey bristled at being asked about the issue.

“I don’t remember you asking me any question like this as peaceful protests were happening, undeterred, inside our state,’’ he said.

But Cara Christ, his health director, acknowledged that the fact a political rally might be constitutionally permitted does not make it safe.

“I think any large group is a potential risk for spreading,’’ she said. Christ said that having an event outdoors does lessen the risk.

“We would recommend any time people attend a large gathering, if you think you’ve been exposed to or are infected with COVID-19 to go get tested,’’ Christ said.

Chris said people should not underestimate the risk of smaller gatherings in spreading the disease.

She specifically is worried about what happens when families get around the Thanksgiving table, especially when children have just returned from college for the holidays. The health director said they may be carrying the virus, noting that the highest rate of infection is among those age 20 to 44.

“They’re going to be coming home and may not be going back to school during Thanksgiving, and then having holiday celebrations,’’ Christ said.

“I hope that I am wrong. But what I anticipate is to see a spike about 10 to 14 days after Thanksgiving, and then, potentially, a continued increase over the next four to six weeks.’’

Ducey’s briefing came on the heels of the health department quietly making changes in the metrics they are using to help school officials determine when to revert to all-online instruction.

All 15 counties are currently classified as having a “moderate’’ threat of spread of the virus

The original recommendation said that schools should consider abandoning in-person instruction if any of the three things being measured move from moderate to “substantial’’ spread That includes the number of cases, the percent of tests coming back positive for the virus, and the percentage of hospital visits by people with COVID-like illness.

Last week the instructions were changed to say that there should be a return to virtual learning only if all three metrics go into the substantial range. That means a spike in cases in a community or county would no longer qualify if, say, hospital visits remain low.

Ducey said too much was being made of the change.

“These adjustments are just that,’’ he said. “They are guidance.’’

The governor said he understands there are teachers with underlying health conditions who may not want to be in school and parents who don’t want their children in a classroom. He said that should be the exception, not the rule.

“Where it is possible and safe, we want our schools open and we want our kids inside a classroom, with a teacher at the front of the classroom, and them getting the best, safest education possible,’’ Ducey said.

The governor said the change was done in consultation with education leaders.

But Chris Kotterman, lobbyist for the Arizona School Boards Association, said the way elected board member around the state found out about it was through the media.

“We weren’t consulted on it,’’ he said. “We don’t like it when fundamental policy changes that impact the operation of public schools are not communicated clearly.’’

The surprise, however, is only part of the problem. Kotterman said school board members “absolutely’’ see the change as having political overtones.

“There definitely are groups out there that believe that schools should be open and are pressuring their local governing boards to just reopen the schools and everything will be fine if only vulnerable people stay home and all that sort of stuff,’’ he said. Added to that, Kotterman said, are statements by Trump saying that the closures are “all politics.’’

Late Thursday, state schools chief Kathy Hoffman weighed in, disputing the governor’s contention that she was involved in the decision.

“The Arizona Department of Education did not request or recommend any changes to the Arizona Department of Health Services school benchmarks,’’ she wrote in a Twitter post.

The governor said he’s anticipating an increase in cases, pointing out the nationwide trend.

“Arizona is no different,’’ Ducey said. What is different, he said, is that the state is better prepared.

“We’ve been through this before and we’ve learned what works to combat this virus,’’ he said. “We’ve had time to prepare.’’

Ducey also said Arizona is doing better than a lot of other states, saying that only 12 other states have a lower rate of infection per 100,000 residents in the past seven days. He said Arizona has the 20th lowest rate of tests for the virus coming back positive.

But the governor omitted one indicator: the effective reproduction rate, a figure he crowed about when in July and August it showed a decrease in spread. As of Thursday, however, it reached 1.16, the highest it has been since June 6.

The more the number is above 1.0, the faster the spread. And the figure puts Arizona among the top 18 states for spread.

Asked about that figure, Ducey brushed it aside.

“There’s a lot of metrics that one looks as they make decisions around this,’’ he said. Still, Ducey said he anticipated the increasing spread.

“This is a virus,’’ he said. “It’s contagious. What we want to do is slow it, contain it to the best of our ability.’’

And when there’s a vaccine?

“We will come as close as we can to stopping it, although if it’s like other viruses, it will likely always be out there,’’ Ducey said. “It’s just at what level.’’