TORONTO -- Joe Biden expressed confidence he will win the presidency as he insisted every last vote be counted, while U.S. President Donald Trump launched multiple lawsuits in hopes of halting vote-counting in three crucial battleground states he can’t afford to lose.

Biden said it’s clear he’s winning enough states to reach the threshold of 270 electoral votes necessary to clinch the presidency. Biden won Wisconsin and Michigan Wednesday, flipping the two Midwestern states Trump won in 2016, and he expects a strong showing among outstanding mail-in ballots in Pennsylvania, where he holds a sizeable advantage.

“I’m not here to declare that we’ve won, but I am here to report that when the count is finished, we believe we will be the winners,” Biden told supporters in Delaware Wednesday afternoon.

Biden also used the moment to call for unity following the bitter campaign. He urged Americans to work harder to listen to each other and leave the divisive election behind them.

“To make progress, we have to stop treating our opponents as enemies. We are not enemies,” he said.

Meanwhile, Trump’s campaign launched several lawsuits in hopes of stopping vote-counting in Michigan, which Biden went on to win, and Pennsylvania and Georgia, which are still counting votes. Trump is also calling for a recount in Wisconsin, which Biden won by more than 20,000 votes. A 2016 recount in Wisconsin changed the margin in Trump’s favour by 131 votes.

Biden called for the democratic process to be carried out to completion.

“No one is going to take our democracy away from us. Not now, not ever,” he said.

In another sign of confidence, the Biden campaign launched a transition website on Wednesday, promising to prepare “at full speed so that the Biden-Harris Administration can hit the ground running on Day One.”

While Biden voices optimism, Trump spent the day sowing confusion. In a series of tweets, Trump baselessly claimed that the election was rigged against him and then declared victory in four battleground states that have not yet reported their final results, or that Biden has already won.

Twitter warned that the claims “might be misleading about an election or other civic process.”

Earlier Wednesday, Trump attacked media organizations for not declaring him the winner, saying in an early-morning appearance that it was "a major fraud on our nation."

"As far as I'm concerned, we already have won this," he said, calling for outstanding ballots not to be counted.

In a tweet later in the day, he seemed to imply the election was being rigged against him.

“Last night I was leading, often solidly, in many key States, in almost all instances Democrat run & controlled,” he wrote. “Then, one by one, they started to magically disappear as surprise ballot dumps were counted. VERY STRANGE.”

Twitter warned that the claim “might be misleading about an election or other civic process.”

The confident tone from Biden comes after his campaign expressed earlier Wednesday that he was “on a clear path to victory.”

“Joe Biden is on track to win this election, and he will be the next president of the United States,” said campaign manager Jen O'Malley Dillon.

In many cases, outstanding votes are from Democratic-leaning areas, she argued.

In Pennsylvania, Gov. Tom Wolf said he had “promised Pennsylvanians that we would count every vote and that's what we're going to do.”

For now, the Associated Press says that it's too early to declare a winner in five battleground states, including Pennsylvania, Georgia and Michigan.

In many key states, a small margin separates Trump from Biden, with large numbers of mail ballots yet to be counted.

The COVID-19 pandemic has led Americans to vote by mail in numbers far higher than normal, which has slowed counts in several states. Democrats appear to be more likely to vote by mail than Republicans.

Why some states are too close to call

Early Wednesday, uncounted mail ballots left the Associated Press saying that it was too early to call the election results in Georgia, North Carolina, Nevada, and Pennsylvania, which between them have 47 electoral votes.

  • Nevada: Mail-in ballots received on election day had not yet been counted in Nevada, along with any mail ballots postmarked no later than Nov. 3 that arrive over the next week and any provisional ballots. The number of outstanding mail ballots is difficult to estimate, because Nevada opted to automatically mail ballots to all active registered voters this year and it’s hard to predict how many will use them.
  • Georgia: While Trump currently leads by two points, an estimated 7 per cent of the vote still remains to be counted, much of it in Democratic-leaning metro Atlanta and Savannah.
  • Pennsylvania: While Trump leads, more than 1.1 million votes are left to be counted, almost all mail ballots. Voting by mail is new to Pennsylvania and all ballots postmarked by Nov. 3 can be accepted if they arrive up to three days after the election.
  • North Carolina: Trump holds a 76,000-vote lead, but there are more than 200,000 mail-in ballots left to count.

Who will control the Senate?

Biden did win in traditionally Republican Arizona, where, though Trump won in 2016, the state's demographics are shifting in the Democrats' favour.

The same tide flipped an Arizona Senate seat to the Democrats, as Mark Kelly won the seat once held by John McCain. Democrats also picked up a Senate seat in Colorado.

Overall, however, control of the U.S. Senate is presently just as hard to call as the presidential race is.

Securing the Senate majority will be vital for the winner of the presidency. Senators confirm administration nominees, including the Cabinet, and can propel or stall the White House agenda. With Republicans controlling the chamber going into the election, 53-47, three or four seats will determine party control, depending on who wins the presidency because the vice-president can break a tie in the Senate.

Democrats needed a net gain of three seats to control the Senate, which they don't clearly have early Wednesday: victories in Arizona and Colorado were balanced by a loss of a seat the party held in Alabama.

In Maine, Republican Sen. Susan Collins is leading, but falling just short of a majority, in her bid for re-election against Democratic challenger Sara Gideon, with about two-thirds of votes reported. Under Maine’s system, if a candidate doesn’t break a 50% threshold in the first-round votes, lower-placed candidates are eliminated until a candidate achieves a majority.

In Georgia, where both Senate seats are being contested this year, at least one is headed to a runoff after no candidate reached the 50% threshold to win.

GOP Sen. Kelly Loeffler will face Democrat Raphael Warnock, in a Jan. 5 runoff special election for one seat. In the other, GOP Sen. David Perdue, the former business executive Trump calls his favorite senator, tried to stave off Democrat Jon Ossoff. It, too, could go to a runoff.

Control of the Senate is key to several measures that a Biden administration might favour, such as expanding the Supreme Court to dilute the current Republican majority, or admitting Puerto Rico or the District of Columbia as states.

Puerto Rico held a referendum on statehood Tuesday, but results have not yet been reported.

Why the election focus may shift from voters to lawyers

With so much at stake in so many narrow races, both parties signalled that the election is likely to move to a series of court battles, with the focus shifting from voters to lawyers.

In the wee hours of Wednesday morning, Trump said he would take the election to the Supreme Court to stop voting, by which he seemed to mean counting.

"If the president makes good on his threat to go to court to try to prevent the proper tabulation of votes, we have legal teams standing by ready to deploy to resist that effort," Dillon said in a statement.

The result of the 2000 presidential election ended up being decided by the U.S. Supreme Court in Bush v. Gore, which led to Republican George W. Bush winning the presidency.

Trump has signalled that he is hoping for a similar outcome.

"If we win, if we win on Tuesday or, thank you very much Supreme Court, shortly thereafter,” he told a crowd at a campaign appearance last week.

Trump has appointed three of the high court's nine justices including, most recently, Justice Amy Coney Barrett.

Across the U.S., 120 proposed state laws and constitutional amendments were on the ballot in 32 states.

Oregon voters decided to decriminalize the possession of small amounts of street drugs, and allow the therapeutic use of psychedelic mushrooms.

Voters in New Jersey and Arizona approved measures legalizing marijuana for adults age 21 and older. Recreational marijuana measures also were ahead in the polls in Montana and narrowly leading in South Dakota.

With files from The Associated Press