ME split its electoral votes four years ago, awarding three to Democrat Hillary Clinton and one to Trump, who won the more rural and conservative of Maine's congressional districts.
The Republican National Committee has prepared for a large-scale legal battle that could come in a razor-thin contest in one of the key states.
Democrats have also amassed their own legal army to fight any potential court battles.
Earlier, when the counting began yesterday, Democrats registered a significant lead in the crucial state of Pennsylvania.
The Wisconsin results won't be officially certified for several more weeks, in keeping with state law, but election administrator Meagan Wolfe made a point of noting she has no reason to doubt them. It ain't over until every vote is counted, but we're feeling good about where we are. That meant a slowdown in the tabulation of results because votes received by mail often take longer to process than ballots cast at polling places.
The president has long charged, with no evidence, that mail-in ballots are a way to cheat in the election. "It is a threat to our democracy and should be suspended until all the votes are counted". A federal judge will hear the challenge on Wednesday morning. Alaska was also too early to call. The House is expected to remain under Democratic control.
"Across the state, dedicated county workers are ready to tirelessly make sure everyone's vote counts", Wolf said.
It is feared that some states, including Pennsylvania, Wisconsin, and MI, may not report results for potentially days.
Twitter permanently suspends Steve Bannon account after he calls for beheadings
The account has been permanently suspended, rather than banned for a limited amount of time, Twitter said in a statement. Any strike temporarily disables uploading for at least a week.
"Millions and millions of people voted for us tonight and a very sad group of people is trying to disenfranchise that group of people and we won't stand for it", Trump said.
Some Trump critics said the actions were insufficient.
This time, media outlets including The Associated Press and others frequently warned a delayed verdict could occur - suggesting that an election where campaigning was so disrupted wouldn't escape seeing its conclusion get scrambled as well.
Mr Trump suggested those ballots should not be counted. "We will be here until the job is done".
But so far, no major incidents have been reported.
With millions of ballots yet to be tabulated, Biden already had received more than 72 million votes, the most in history. Poll workers guessed this was due to an unprecedented wave of early voting. Here's what you need to know as you start your day. "We don't want them to find any ballots at 4 o'clock in the morning and add them to the list". If that doesn't work, Billman told CNN, each vote may have to be manually duplicated by a poll worker using a touch-screen voting machine, with a witness observing the process.
Dozens gathered in Detroit Wednesday afternoon, in a square across from the city's election commission office.
While voting appeared to be going smoothly in most places, there were some scattered glitches.
"He's calm, chilling", said a source familiar with the scene.