Donald Trump lashed out on Monday at Republicans who have tried to tone down his rhetoric about election fraud, calling his own party's leaders "so naive" and claiming that large-scale voter fraud is real.
The defensive barrage comes as Republicans are under pressure to rebuke Trump's claims that the presidential election is "rigged" in Hillary Clinton's favor. The GOP push reflects growing worries that their nominee's unsubstantiated rhetoric could erode public trust in elections and lead to damaging disputes if he loses.
Some voters have raised uncertainty about the legitimacy of the election in the wake of Trump's comments.
Those doubts have some local supervisors of elections worried, including Clay County elections supervisor Chris Chambless, who heads the state association of elections supervisors.
READ: Open letter to Florida voters on election fraud
“What concerns me is that individuals hear the stories, give them credence and will choose to stay home,” Chambless said. “This is the most important election -- a presidential election. It is our Super Bowl.”
Chambless said the election system is constantly monitored. He said that statewide the tabulation process is a closed network and is not connected to the internet or an outside network.
In St. Johns County, many were picking up absentee ballots on Monday. Some put little stock in the “rigged election” claims.
“I think it's a ridiculous statement,” voter Rob Lucas said. “I mean, come on.”
Vicky Oakes oversees the elections office in St. Johns County, and she said she gets upset when people say they're not voting because the outcome has been decided already.
“It's not rigged. It's the truth of the matter. It's not,” Oakes said. “Supervisors and every election official I know, we work very hard to make sure every voter has an opportunity -- to count every vote accurately.”
Trump's running mate, Mike Pence, declared Sunday the ticket will "absolutely accept the results of the election." But Trump seemed to brush back against his vice presidential pick.
"Of course there is large scale voter fraud happening on and before election day. Why do Republican leaders deny what is going on? So naive!" he tweeted Monday.
Trump says own party being 'naive'
There is no evidence to back up Trump's claim of widespread voter fraud. A study by a Loyola Law School professor found that out of 1 billion votes cast in all American elections between 2000 and 2014, there were only 31 known cases of impersonation fraud.
Trump's tweets on voter fraud zeroed in another source of tension among Republicans. GOP leaders often raise the risk of fraud as they make a case for tightening access to the polls through voter identification laws and other restrictions. But Trump's often repeated claim that the election is "rigged" has put the party in the unusual position of having to express faith in the legitimacy of the election system.
Leaders in both parties fear Trump's claims will encourage his most ardent supporters not to accept the results, leading to prolonged litigation, possible violence or hardened divisions -- or some combination of the three. That could make it even more difficult to govern and could take a long-term toll on the democracy.
Even staunch conservatives have found themselves in the position of trying to gently walk back the nominee's remarks.
"I just don't think it's that constructive to make this a campaign issue," Rep. Steve King of Iowa said Monday on CNN. He said he shares Trump's worries about election fraud, but acknowledged Trump's claims are "partially unsubstantiated."
"I don't want to say anything on this program that delegitimizes our election," King said.
Pence urges respectful vigilance
Pence said at a Monday rally in Cincinnati, Ohio, that "voter fraud cannot be tolerated" and respectful vigilance is the best way to prevent a "rigged election."
The Republican vice presidential candidate said too high a price was paid for the right to vote.
But Pence urged those who monitor polling sites to do so "respectfully" to ensure an "outcome we can all be proud of."
Pence says the media is "rigging the election" by writing critical stories of Trump. But he has stopped short of suggesting voter fraud will have an impact on the result.
Rep. John Lewis rebuts Trump
Congressman John Lewis says the Nov. 8 presidential election will be a fair one that "we are all going to be very proud of all across the country."
The Georgia Democrat made the comment in response to Trump's “rigged election” claim.
Lewis is no stranger to ballot access issues. He was beaten as he peacefully demonstrated for ballot access during the civil rights movement.
Lewis said Trump is "fanning the flames of division," adding that, "It's unfortunate he is saying that before we have even voted."
He commented Monday before he cast his ballot on the first day of early voting in Georgia.