Biden leads Trump 253-214.

Biden is projecting confidence, the campaign even has a stage ready in Wilmington, Delaware and microphones are being tested -- sending out strong visual cues for a big announcement tonight.

Trump, meanwhile, is angry and showing it, in tweets and in claims of victory, live streamed from the White House press briefing room.

Right now, loads of mail in ballots are getting counted in Penn State and Trump's lead here is shrinking at an alarming rate. Biden is winning the final batch of mail in ballots at a rate of anywhere from 50 to 70 per cent and melting away the distance between himself and Trump.

In the hours between 5 p.m. and 9 p.m. EST, Trump's lead has shrunk from around 90,000 votes to just over 50,000 votes and there are still more than 300,000 votes to be counted.

The late counting is favouring Biden heavily. These are all ballots that were not processed until Election Day, based on state law.

Trump spent months claiming that voting by mail would lead to widespread voter fraud. He spent the entire day on Thursday railing against "illegal" mail-in ballots.

Trump won Pennsylvania in 2016 by less than a percentage point. The Democrats are hoping to flip it and recreate their "blue wall" in the upper MidWest. They have already won Michigan and Wisconsin.

For Trump to win a second term, he needs Arizona which has already been called by Associated Press and Fox News for Biden. Trump has criticised the Arizona decision, where the gap has been shrinking steadily. Trump needs to win the remaining vote at a steady clip of 59 per cent to win the state. Biden's lead has gone from 9 percentage points to 4.2 and now further down. Biden's count was higher by 46,257 votes at 9 p.m. EST Thursday. It was double this number 24 hours ago.

Could this be a replay of that night in 2000 when Florida was called for Al Gore, and then for George W. Bush, and then went to the Supreme Court for resolution? This is where things stand at 9 pm EST on Thursday.