Election 2020 updates: Biden warns of 'dark winter,' pushes masks in pandemic plan

Following a tight Senate race, Sara Gideon, a Democrat and speaker of the Maine House, has conceded to longtime Maine Sen. Susan Collins.

Gideon said Wednesday that she spoke with Collins and congratulated her.

"I told her that I will always be available to help serve the people with me," Gideon said.

"Regardless of the result, together, we built a movement that will help us make progress for years to come," she added.

At an outdoor COVID-19 compliant party Tuesday night, Collins touted her history of never missing a vote in the Senate, more than 7,400 votes over 24 years.

Twitter hit one of Trump's morning tweets with a label saying the content is "disputed and might be misleading about an election or other civic process."

In a tweet posted just after 10 a.m. ET, the president claimed that "surprise ballot dumps" are stealing the election away from 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, and the 'pollsters' got it completely & historically wrong!"

In a follow-up tweet Wednesday morning, the president doubled down on his misleading claims about mail-in ballots, writing: "How come every time they count Mail-In ballot dumps they are so devastating in their percentage and power of destruction?"

The president has repeatedly attacked mail-in ballots throughout the campaign.

This late blue wave is not surprising because early voting and mail-in ballots were expected to be heavily Democratic.

Majority Leader Mitch McConnell said Wednesday that he thinks President Trump "ran a heck of a race."

"Everybody was writing him off," McConnell said. "He went out and really worked himself to death for the last two months with multiple rallies every day and turned it into a cliffhanger against everybody's expectation."

 Asked about the president falsely declaring victory, McConnell said, "It's not unusual for people to claim they've won the election, I can think of that happening on numerous occasions, but claiming you've won the election is different from finishing the counting."

"What we're going to see here in the next few days both in the Senate races and in the presidential race is each state will get to a final outcome and you should not be shocked if both sides are going to have lawyers there, both in these close Senate races and in the presidential contest," he said.

McConnell also changed his timeline on COVID-19 relief, saying he believes the Senate needs to do a relief package "before the end of the year." That's a departure from comments he made just before Election Day that relief ought to be taken up "right at the beginning" of next year. 

-ABC News' Allie Pecorin

Former Vice President Joe Biden has 69,543,071 votes tallied for him so far, breaking a record of most votes for any presidential candidate.

In 2008, then-candidate Barack Obama made history by winning 69,498,516 total votes, according to the FEC -- the most of any presidential candidate in history at that time. 

-ABC News’ Quinn Scanlan