Hundreds of people are expected to descend on the city for the rally, and security barricades have already been installed around the US Capitol to avoid the destruction that was witnessed on 6 January.
Mr Graham, who despite being an on-and-off ally of Donald Trump, criticised the rioters for assaulting Congress in January. He told The New York Times that law enforcement needed to be firm with protesters at the upcoming demo, which has been dubbed “Justice for J6”.
“They need to take a firm line, buddy,” Mr Graham said of law enforcement officials, who are on high alert ahead of Saturday’s demonstration. “If anybody gets out of line, they need to whack ’em.”
Many of those who are planning on taking part, according to reports, are so-called Capitol riot “truthers” who believe it was “no big deal,” as Heidi Beirich, co-founder of the Global Project Against Hate and Extremism, told The Associated Press.
Nancy Pelosi, the Democratic speaker of the House, agreed with that assessment on Wednesday when she told reporters that rioters were “coming back to praise the people who were out to kill”on 6 January.
An internal memo from the Capitol Police, as seen by CNN, said officers were preparing for the possibility of violence during the demonstration, which could see some 700 attendees.
Intelligence officials told The Associated Press this week extremists groups such as the Proud Boys and Oath Keepers, whose members were involved in the 6 January assault,
Another Republican senator, Tommy Tuberville, meanwhile told the Times that he did not believe “a lot of people” will attend the rally, after federal instigators arrested more than 600 people in connection the January Capitol riot.
“I don’t expect a lot of people there,” the Alabama Republican said, appearing to downplay the demonstration. “I haven’t heard anything about it. I will not be there”.
Mr Trump, who was condemned for saying he “loved” the rioters who assaulted the US Capitol on the back of his election lies, is allegedly planning to play golf in New Jersey on Saturday to avoid any further damage to his reputation, people familiar with his plans told the Times.