Joe Biden holds a clear advantage over United States President Donald Trump across four of the most important presidential swing states, a new poll shows, backed by the support of voters who did not participate in the 2016 election and who now appear to be turning out in large numbers to cast their ballots on Tuesday, mainly for the Democrat.
Biden, 77-year-old the former US vice president, is ahead of Trump, a Republican, in the Northern battlegrounds of Wisconsin and Pennsylvania, as well as in the states of Florida and Arizona, according to a poll of likely voters conducted by The New York Times and Siena College.
His strength is most pronounced in Wisconsin, where he has an outright majority of the vote and leads Trump by 11 points, 52 per cent to 41 per cent, the Times reported on Sunday, two days ahead of the November 3 presidential election.
But US President Trump, 74, appeared confident on Sunday, tweeting that "Our numbers are looking VERY good all over. Sleepy Joe is already beginning to pull out of certain states. The Radical Left is going down!"
Biden's performance across the electoral map appears to put him in a stronger position heading into Election Day than any presidential candidate since at least 2008, when in the midst of a global economic crisis Barack Obama captured the White House with 365 electoral college votes and Biden at his side.
Trump's apparent weakness in many of the country's largest electoral prizes leaves him with a narrow path to the 270 Electoral College votes required to claim victory, short of a major upset or a systemic error in opinion polling surpassing even the missteps preceding the 2016 election, the report said.
Should Biden's lead hold in three of the four states tested in the survey, it would almost certainly be enough to win, and if he were to carry Florida, he would most likely need to flip just one more large state that Trump won in 2016 to clinch the presidency over his Democratic rival Hillary Clinton.
In the closing days of the campaign, Biden has a modest advantage in Florida, where he is ahead of Trump by three points, 47 per cent to 44 per cent, a lead that is within the margin of error. He leads by six points in both Arizona and Pennsylvania. In no state did Trump's support climb higher than 44 per cent, the report said.
The margin of error is 3.2 percentage points in Wisconsin and Florida; 3 points in Arizona and 2.4 points in Pennsylvania.
Biden, 77, has consistently held the upper hand over 74-year-old Trump across the electoral map in polling conducted by The Times since late last spring. While that advantage has varied over time, and has differed from state to state, he has at no point slipped behind Trump in any of the swing states that are likeliest to decide the election.
Biden, in a tweet, wrote that "We have in our hands the ultimate power: the power of the vote. Don't let it go to waste. Make your plan to vote today."
Meanwhile, a CNN reported that Biden holds an advantage in the upper Midwest states of Wisconsin and Michigan, but the race between Biden and President Trump is tighter in the battlegrounds of Arizona and North Carolina.
Trump won all four of these states in 2016, and a loss on Tuesday in any of them would make his narrow path to 270 electoral votes more difficult.
The polls, conducted as the campaign comes to its close, show little movement in the presidential race compared with previous CNN polls in each state.
The surveys suggest Biden has banked a broad advantage among those voters who have already cast their ballots by mail or through early in-person voting, with Trump leading by a wide margin among those who have yet to vote. The size of that bloc of later voters could dictate the outcome of the race.
In Arizona and Wisconsin, the poll results are roughly in line with an average of recent high-quality public polling on the race. The Arizona survey shows a race within the poll's margin of sampling error, with Biden at 50 per cent support to Trump's 46 per cent. In Wisconsin, Biden has the lead, with 52 per cent behind him vs 44 per cent for Trump.
The North Carolina result shows Biden narrowly ahead of Trump, 51 per cent to 45 per cent, just outside the poll's 4 point margin of sampling error.
The average of public polling in North Carolina suggests a slightly tighter race for the presidency than does the new poll, though an NBC News/Marist College poll there this week also found Biden with a narrow advantage.
In Michigan, the results suggest a wider margin than most public polling there, with 53 per cent for Biden to 41 per cent for Trump, but the results for each candidate are within the survey's margin of error of the average estimated support for that candidate.
The CNN Polls in Arizona, Michigan, North Carolina and Wisconsin were conducted by telephone from October 23 through 30 among random samples of roughly 1,000 adults in each state.
That included 865 likely voters in Arizona, 907 likely voters in Michigan, 901 likely voters in North Carolina and 873 likely voters in Wisconsin. Results among likely voters have a margin of sampling error of plus or minus 4.1 percentage points in Arizona, 3.8 points in Michigan, 4.0 points in North Carolina and 3.9 points in Wisconsin. It is higher among subgroups.