US citizen holding a rifle. (Reuters)

More than two-fifths of US citizens consider a civil war inevitable in the next ten years, a figure that rises to more than half among self-identified "strong Republicans."

The findings of YouGov and the Economist research follow similar results in previous polls.

US Senator Lindsey Graham warned on Sunday of "riots in the streets" if former US President Trump faces charges over his handling of documents found when the FBI searched his Mar-a-Lago home.

His remarks prompted widespread anger.

On Monday, Mary McCord, a former acting deputy attorney general, said, as quoted by CNN, that it was “incredibly irresponsible for an elected official to basically make veiled threats of violence, just if law enforcement and the Department of Justice … does their job”.

Stating “People are angry, they may be violent”, McCord added, indicating “what [Trump] knows and what Lindsey Graham also knows … is that people listen to that and people actually mobilize and do things”.

"January 6 was the result of this same kind of tactic by President Trump and his allies," he stressed.

The January 6 Capitol attack left seven people dead and more than 100 officers injured, including four officers who later committed suicide. More than 700 persons have been charged as a result of the investigation.

According to a YouGov and the Economist poll, 65% of all respondents believe political violence has increased since the beginning of 2021. Furthermore, 62% expected political violence to increase in the coming years.

Eyeing its long history of political violence and assassination, current rising radicalism and fighting words increase jagged political division and explicitly warn of inevitable political violence.