The Johns Hopkins survey found the percentage of adults believing that threatening public health officials was justified rose from 15% to 21% from November 2020 to the summer of 2021.

The biggest increases were among respondents who were male, identified as Hispanic and who were Republicans. There were also increases among those earning $35,000-$74,999 and $75,000 or higher.

Go deeper: While former President Trump has been blamed for stoking a divisive political climate and flouting public health measures, researchers found sentiment for harassment and threats continued to rise after President Biden took office and amid optimistic projections about vaccinations and falling case rates.

Most respondents who thought attacks on public health officials were justified felt the same way about attacks on politicians, possibly reflecting the view that health officials make inherently political decisions, the researchers said.