Trump and Allies Raise Concerns About Voter Intimidation on Election Day Trump has called on his supporters to watch polling places on Election Day.

 -- In less than 48 hours over the weekend, Republican presidential nominee Donald Trump spoke or tweeted more than 20 times about his belief that the election process is “rigged.”

While concerns about the integrity of the election have been tempered by a number of prominent members of the GOP, fears about voter intimidation, particularly after the firebombing and vandalism of a Republican Party office in North Carolina, are causing anxiety in the party.

At a rally in Altoona, Pennsylvania, in August, Trump encouraged his supporters to “go around and look and watch other polling places,” arguing that the only way he would be beaten in the general election is if “in certain sections of the state they cheat.”

During a campaign rally in Novi, Michigan, in September, he told attendees, “Go to your place and vote. And go pick some other place and go sit there with your friends and make sure it’s on the up and up.”

hHe added, “So go and watch these voting places.”

Political parties and candidates may appoint poll watchers; however, states differ on the number of observers who are allowed and their qualifications. Trump includes a form on his website so people can sign up to be a volunteer election observer. According to the National Conference of State Legislatures, partisan observers, or poll watchers, are “not supposed to interfere in the electoral process apart from reporting issues to polling place authorities and party officials.”

“I’ll look for ... well, it’s called racial profiling. Mexicans. Syrians. People who can’t speak American,” a Trump supporter from Ohio told The Boston Globe. “I’m going to go right up behind them. I’ll do everything legally. I want to see if they are accountable. I’m not going to do anything illegal. I’m going to make them a little bit nervous.”

Surrogates for the Republican nominee have been pointing the finger at Democrats for allegedly employing voter intimidation tactics, as well as fraud, to manipulate past election results.

In an interview on ABC’s “This Week,” former Speaker of the House Newt Gingrich alleged that voter fraud and intimidation were widespread ranging back to 1960, when, in his view, the presidential election swung to John F. Kennedy as a result.

“You look at Philadelphia, you look at St. Louis, you look at Chicago, I mean, again, I’m old enough, I remember when Richard Nixon had the election stolen in 1960, and no serious historian doubts that Illinois and Texas were stolen,” said Gingrich. “So to suggest that we have — that you don’t have theft in Philadelphia is to deny reality.”

References to voter intimidation in Philadelphia often allude to a 2008 incident in which two members of the New Black Panther Party, one of whom held a billy club, stood outside a polling location and allegedly pointed and shouted at voters.

While it has been surrogates of the Trump campaign raising alarm over the possibility of voter intimidation in November, he discussed plans that would violate anti-intimidation laws if they are carried out on Election Day.

At the Altoona rally he addressed fears of voter fraud in the state, saying he wanted police officers in place to ensure the integrity of the vote.

“We have a lot of law enforcement people working that day. We’re hiring a lot of people,” said Trump. “And we have to call up law enforcement. And we have to have the sheriffs and the police chiefs and everybody watching.”

However, Pennsylvania law prohibits police officers and soldiers from being within 100 feet of polling places unless they are voting themselves or responding to a call to keep the peace.

Discussions of fraud and intimidation appear likely to continue over the campaign’s final three weeks. Today Trump called Republican leaders “naive” for dismissing his claims.

Former New York City Mayor Rudy Giuliani, now an adviser to Trump, joined the candidate’s calls this weekend, pinpointing “dead people” as a concern, asserting they “generally vote for Democrats rather than Republicans.”

“I can’t sit here and tell you that they don’t cheat. And I know that because they control the polling places in these areas,” Giuliani said of “inner cities” in an interview with CNN on Sunday. “There are no Republicans, and it’s very hard to get people there who will challenge votes. So what they do is, they leave dead people on the rolls and then they pay people to vote as dead people, four, five, six, seven.”

ABC News’ Chris Donovan contributed to this report.