The US presidential election is expected to see a record turnout, with polls analysts attributing this to the Americans' bid for a change.

More than 91.6 million Americans have already voted, mostly through mail-in ballots, which faced unproved accusations of fraud by President Donald Trump but got strong support from the Democratic Party candidate Joe Biden.

These votes represent about 43 percent of registered voters nationwide, according to a survey of election officials in all 50 states and Washington, DC, by CNN, Edison Research, and Catalist corporation.

David J Becker, executive director and founder of the Center for Election Innovation & Research, Washington, DC, says they estimate turnout of 150 million in total out of about 240 million eligible American voters.

"This means 20 million more Americans will be voting this election than that of 2016," he said during an interaction with a group of journalists virtually participating at the 2020 US Presidential Election Reporting Seminar (Oct 25-Nov 7) organised by the Hawaii-based East-West Centre.

Referring to voting data, he said on Friday that 50 million mail-in ballots have already been returned to the election office and about 40 million others are expected to be returned by November 3. Besides, 40 million Americans have cast ballots in person during the early voting period. The rest are expected to vote on the Election Day on November 3.

"We don't see the high voter turnout to keep the thing same. That's not a thing in American society. This means they want a change," said David Becker.

In some of the elections with lowest turnout, the presidents were reelected. One of the examples could be reelection of Bill Clinton in 1996 with low voter turnout of 49.2 percent. Voter turnout in the last few US presidential elections ranged between 55-60 percent, but analysts say it is likely to be beyond 70 percent this time.

Analysts say mail-in voting saw a significant surge this year. Such voting in 2016 was only 25 percent or roughly 32 million, so far the highest in US history though the US has the mail-in voting system for 200 years.

They say the pandemic, democrat supporters' more enthusiasm against Donald Trump's attack against mail-in vote and expansion of voters' education for months led to the surge in mail-in voting.

Christian Ulvert, a Democratic strategist, and founder and president of EDGE Communications LLC, Miami, Florida, says voting pattern appears to have a shift during this election.

Usually, the senior citizens, especially the White male Republicans, go for mail-in voting because of their old-age complication. This year, however, they are voting mail-in in less numbers, he said.

Ulvert said on the other hand, the Democrat supporters have opted for mail-in voting in much higher numbers -- first because they are more aware of Covid-19 and second because they want to prove wrong Trump who questioned the integrity of the mail-in voting system. Also, many of the Latino people and African Americans are opting to vote early and in higher numbers compared to that of 2016.

Apart from the mail-in voting, he said, long lines of voters are being observed in the competing states for early voting, he said.

"Probably, we are going to see about 80 percent of voter turnout this election," Christian Ulvert said.

Analysts say US elections depend on electoral votes, not the national popular votes. That means, in the states, people vote the electors who form Electoral College of 535. Including three additional electors from the District of Columbia, a total of 538 electors elect the president. Any party having majority electors in a state means all the electors will vote for the winning party.

Republican and Democrats know for sure some states where they will surely win or lose. However, some states are swing states. In this election, Joe Biden remains ahead in the opinion polls in some of the swing states -- Florida, North Carolina, Pennsylvania, Ohio, Michigan, Arizona, Wisconsin, and Iowa.    

Democrat candidate Hillary Clinton too was ahead in most polls before the 2016 election and got 2.9 million more national popular votes. Yet, she was defeated by Trump as he received 304 electoral votes when he needed 270.

"No matter who the president is, we are going to see high turnouts of voters. I hope this stays for decades. Hopefully, the Democrats as well as the Republicans will appreciate this," said Christian Ulvert.