Ballot counting underway in several states

Others wait until Election Day - NBC's Tom Costellos examines how it works, and how long it could take

WASHINGTON, D.C. (KYMA, KECY) - Election Day is still hours away, yet more than 90-million Americans have already cast their votes.

In some states, election workers are already counting those ballots, but the final tally in other major battlegrounds could be delayed for days, or even longer. Experts predict early voting could lead to a slew of later problems.

It's the counting countdown. In just hours, all 50 states will be in the process of tallying ballots.

But with thousands of mail-in votes expected to arrive after Election Day, experts say it could take days, or even weeks, to determine the final results. That's something President Donald Trump has falsely claimed could lead to election fraud.

"I think it's a terrible thing when states are allowed to tabulate ballots for a long period of time after the election is over, because it can only lead to one thing, and that's very bad." said the President Saturday during a rally in Pennsylvania.

In fact, no Presidential Election has ever been officially determined on Election Night.

But this year, record early turnout could make the ballot bottleneck even worse. So far, more than 93-million people have already made their presidential pick. That's more than double the early voting numbers from 2016.

While the count is already underway in Florida, Arizona, and North Carolina, other battlegrounds like Ohio, Wisconsin, Michigan, and Pennsylvania won't begin counting millions of mail-in ballots until Tuesday.

Ohio's Republican Secretary of State says they will count ballots arriving 10-days after Election Day if they're postmarked by Election Day.

" President Trump is suggesting any votes counted after election day could be fraudulent and should not be counted. Is that the way it goes in Ohio?" asks NBC's Tom Costello.

"No, simply not true that's not the way that it works here in Ohio. The law in the state of Ohio is very clear about how this process works. Election Night is important it's when people stop casting ballots but it's certainly not when the elections process is over." said Secretary of State Frank LaRosa.

The decision delay potentially setting the state for post-election litigation.

"The reason why the counting process takes a while, is because it's addressing the exact concerns that the President has expressed. they're double checking and triple checking their math before ultimately declaring and certifying a winner." said Matthew Sanderson, an NBC News Election Law Analyst.

Pennsylvania's Secretary of State admits the final count sill take days.

"This is a process and we want to make sure that every single vote of every valid voter is securely and accurately counted." said Kathy Boockvar during a Sunday appearance on Meet the Press.

In Michigan, where every voter received an absentee ballot application, most of the mail-in processing is done by hand. That further slows tabulation. Results there may not be until the end of the week.

Some experts estimate more than a million mail-in ballots could be rejected. The most common reasons include a missing signature or a late arrival. And those uncounted votes could make all the difference in a tight race.

Experts also raise the possibility of results swaying as Election Night goes on. They say Democrats were more likely to vote by mail this year. So in some states it may look like Republicans are making a stronger showing early in the night. However, once all the mail-in ballots are counted, the final result may tell a different story.