Democrat Hillary Clinton's campaign has predicted a strong turnout among key groups such as Hispanics and African-Americans, while advisers to Republican Donald Trump say the large crowds at his rallies show enthusiasm that could help deliver a win at the polls.
Both candidates on Sunday were to campaign heavily in key swing states including Ohio, Pennsylvania and New Hampshire ahead of Tuesday's presidential election.
"We're feeling very solid going into this last weekend," Clinton campaign chairman John Podesta said on NBC's "Meet the Press." "But there's a tremendous amount of work to do."
Trump campaign manager Kellyanne Conway, speaking on a call with reporters through the Republican National Committee, said Trump is expanding his reach to historically Democratic states and is "now competing in states where people wrote us off months ago."
"If they thought Michigan was in the bag, Hillary Clinton, Bill Clinton and Barack Obama would not be returning there," she said.
In the final stretch of the campaign, a scuffle broke out at a Trump rally in Reno, Nevada, on Saturday night and the Republican candidate was rushed off stage by the Secret Service when someone in the crowd shouted "gun."
The incident started when a man held up a sign that said "Republicans against Trump." No gun was found.
The latest Reuters/Ipsos poll shows Clinton with a 5 percentage point lead over Trump in the national survey - 44 per cent to 39 per cent support - while races in the swing states of Florida, North Carolina have shifted from Clinton's control to being too close to call. The Reuters/Ipsos States of the Nation project estimates that Clinton has a 90 per cent chance of winning the election.
Podesta said Clinton's base of support among minority voters and the large number of early votes cast will lead to a win for her.
"We've had college-educated women voting in higher numbers, voting for her in higher numbers. Asian-Americans voting disproportionately," Clinton campaign manager John Podesta said on "Meet the Press."
The Clinton campaign in recent weeks has deployed its most high-profile allies including President Barack Obama, first lady Michelle Obama, and pop stars such as Beyonce and Katy Perry to attract minority and young voters who have so far been cool to support Clinton.
Podesta, appearing on ABC's "This Week," said the Clinton campaign believes it can match the numbers Obama pulled in his 2012 re-election campaign with African-Americans.
Trump's running mate, Indiana Governor Mike Pence, on Sunday pledged Trump's campaign would accept a "clear outcome" to the election but said both campaigns reserved legal options if there was a disputed result.
"The campaign has made it very clear that a clear outcome, obviously, both sides will accept," Pence said.
"But I think both campaigns have also been very clear that in the event of disputed results, they reserve all rights and remedies."
Trump faced criticism from both Democrats and fellow Republicans for refusing to say at the third and final presidential debate last month if he would accept the election result, instead saying he will evaluate the outcome "at the time."
