Democratic presidential nominee Joe Biden has warned that he would not let President Donald Trump declare victory in today's election before the results are clear.
"My response is the President is not going to steal this election," Mr Biden told newsmen on Sunday during a campaign stop in Philadelphia.
Mr Biden also condemned efforts by supporters of Mr Trump to intimidate his backers, including an incident last Friday on a Texas highway and a partial shutdown of New Jersey's Garden State Parkway earlier on Sunday.
"Folks, that's not who we're," he said. "We're so much better than this."
Mr Biden was responding to a report in Axios that Mr Trump has told associates he intends to declare victory early if the results show him ahead, even if the outcome is not really known.
Speaking to newsmen in Charlotte, North Carolina, Mr Trump denied the report, but also criticised the counting of late-arriving ballots as "terrible" and said his campaign intended to fight it.
Mr Biden, a previous VP, urged supporters in the Democratic stronghold city to push past Mr Trump's efforts to discourage them from going to the polls, as he kicked off a two-day final swing through the potentially pivotal state of Pennsylvania.
"Every day is a new reminder of how high the stakes are, of how far the other side will go to try to suppress the turnout, especially here in Philadelphia," Mr Biden said.
"President Trump is terrified of what will happen in Pennsylvania. He knows that the people of Pennsylvania get to have their sayif you have your say, he doesn't stand a chance."
Mr Biden spoke at a drive-in "Souls to the Polls" rally for black voters, invoking the legacy of the late civil rights leader and Georgia Representative John Lewis.
"Freedom is not a state. Freedom is an act," he said, quoting Mr Lewis, and then adding: "We've to defend it; we've to vote."
The Biden campaign is focused now on getting black voters to the polls since they are more likely than white voters to prefer to vote in person on election day.
The campaign is also hoping to narrow the wide margins in rural areas that helped Mr Trump edge out Mrs Hillary Clinton in the state by 44,000 votes in 2016.
Mr Biden has been ahead in Pennsylvania polls, including a New York Times/Siena College survey out on Sunday that showed him leading 49 per cent to 43 per cent.
But his campaign has made clear that it's concerned about turning out its voters, sending Mr Biden into Pennsylvania on Sunday and again yesterday, when he, his wife Jill, his running mate Kamala Harris and her husband Doug Emhoff will all barnstorm the state.
Democrats have a substantial lead in early voting, having returned nearly 1.6 million ballots as at last Saturday, while Republicans had returned 542,000 ballots and voters with no party affiliation had returned 238,000 ballots.
State law forbids the processing of those ballots before 7am on election day, a rule that Democrats fought but Republicans, who expect a larger proportion of their votes to be cast today, defended.
BLOOMBERG