Some of Trump's supporters said they were taking their cue from the candidate. In August he made the extraordinary claim — one he did not back up with any evidence — that the election will be fixed. That assertion threatens the American tradition of peacefully contested elections and the essence of a fair democratic process.
Trump has continued to make the charge at other rallies. In Michigan on Friday, for example, Trump urged supporters to vote and then go to a different polling place with friends and make sure "it's on the up and up." He said voter fraud is "a big, big problem in this country" but "nobody has the guts to talk about it."
While raising such unsubstantiated concerns about the fairness of the election, Trump said in Monday's first general election debate he would abide by its result. Though he initially dodged moderator Lester Holt's question about accepting the outcome, Trump eventually said of Clinton, "If she wins I will absolutely support her."
The poll also found that nearly 8 in 10 Americans say they favor requiring voters to provide photo identification in order to vote, while just 1 in 10 are opposed.
"Any objection to having to show voter ID is just wrong," said Etan Markowitz, 76, a Democrat from Culver City, California, who is crossing party lines to vote for Trump. "I think there is voter fraud: people voting more than once, and early voting and absentee ballots give too many opportunities for fraud. We need extensive reform."
Democrats worry that strict voter ID laws could lead to the disenfranchisement of poor, often minority voters who don't have ID.
While most Americans feel that new technologies have made vote counting more accurate overall, many have at least some concern about hackers interfering with the election. Forty-one percent say they're extremely or very concerned and 35 percent who say they're somewhat concerned. Fifty-two percent of Republicans and 35 percent of Democrats say they're extremely or very concerned.
The top Democrats on the House and Senate Intelligence Committees say they've concluded Russian intelligence agencies were trying to influence the U.S. presidential election. On Friday, a Homeland Security Department official told the AP that hackers have targeted the voter registration systems of more than 20 states in recent months. The official was not authorized to discuss the matter publicly and requested anonymity.
Julio Carmona, a 31-year-old Clinton supporter from Bridgeport, Connecticut, asked: "If these people can go into the DNC and hack, who is to say that that can't get there and sway the vote to Trump? What if the Russians really can do something like that?"
The AP-NORC poll of 1,022 adults was conducted Sept. 15-18 using a sample drawn from NORC's probability-based AmeriSpeak panel, which is designed to be representative of the U.S. population. The margin of sampling error for all respondents is plus or minus 3.7 percentage points.
Respondents were first selected randomly using address-based sampling methods, and later interviewed online or by phone.