Republican and independent voters are twice as likely to not reveal their true preference for president in a telephone poll, a study found.

CloudResearch, an online market research and data collection company, found that 11.7% of Republicans and 10.5% of independents said they wouldn't share their true opinion, while only 5.4% of Democrats said the same.

"That raises the possibility that polls understate support for President Donald Trump," Bloomberg reported Friday.

According to CloudResearch, some survey responders said they thought it would be "dangerous" to express an opinion outside the "current liberal viewpoint."

While the survey was conducted online, inquiries about the results were made via phone interviews.