Election Day is approaching, and many people in the U.S. might have questions about how votes will be counted after the polls close. Depending on your location, you may cast your ballot for various positions, including school boards, city councils and mayors.

This year, more states will likely be decided by very narrow margins. This could lead campaigns, or even foreign actors, to try to create more distrust among voters during the ballot-counting process. However, if you know what to look for, this situation will appear much less chaotic.

The chaos of the 2020 election can be attributed, in part, to significant shifts in ballot counting. Initially, results from traditionally Republican districts showed Donald Trump in the lead. However, as the counting continued, ballots from blue counties began to come in, allowing Joe Biden to surge ahead.

This is why you might remember Trump saying, "Stop the count." It became clear that Biden had won several close states as all the votes were counted.

On Wednesday, ABC News' "Start Here" podcast host Brad Mielke spoke with Michael McDonald, a professor of Political Science at the University of Florida, who has been studying how votes are counted for years.

START HERE: Professor McDonald, let’s assume everyone’s voted on election night, polls are closed. We often see the thing where it's like "2% of precincts in, we are not projecting anything yet." What sort of complicating factors would make those early numbers not indicative of the fuller results? Like what kind of twists and turns are you expecting?

MCDONALD: Yes, so we tend to see smaller localities be able to count their ballots and report them faster. And then larger localities tend to take a little more time because they have more ballots to process. And so we get this discrepancy where, because Republicans tend to live in more rural areas that are smaller, those ballots may be counted first or reported first. But, and then the urban areas may count their ballots or report their ballots later. So there's nothing nefarious going on. It's just the timing of the the workload that election officials have that leads to the timing of when the ballots are going to be reported.

START HERE: OK, this is what I wanted to ask you about. I’ve heard phrases like “red mirage,” a “blue shift.” That’s what you’re describing here, right? When it takes a while to count mail-in ballots, it looks like one party is way, way ahead.

MCDONALD: Yeah, it really depends on the state. So some states we have this lead time. Florida, for example, where I live, does have lead time, where election officials are already doing all the preparation they need so that they can be out of the gate very fast. And because we tend to suspect, although this election could be a little different, we suspect that those early voters are going to be more Democratic leaning.

We could have a blue mirage and then a red mirage, but then a blue mirage again, because election officials are counting the ballots that came back on Election Day. And, and those could be Democratic leaning or they may not be. This election, there are some trends and dynamics that are different than the past. So the past is not necessarily a good guide as to what may happen with mirages this time around.

START HERE: Yeah, tell us about that with the early voting especially, because four years ago there was this huge disparity by party, right? Democrats were all about early voting. They were all about voting by mail. Republicans were largely told by the president at the time "Vote on Election Day," and they did. Is that going to hold true this year?

MCDONALD: Well, we can already see that it's not true. And Donald Trump has given the green light to his supporters to vote in-person early. And we can certainly see Republicans showing up in large numbers to vote in-person early compared to any past election that we've seen with the in-person early vote. Before 2020, we would have said, yeah, that in-person early vote, that's when all the Democrats vote. And it's really the mail ballots where Democrats vote.

But the pandemic flipped that around. And so now Democrats are the ones who are much more likely to vote by mail. Of course, Trump continues to call mail ballots fraudulent. And so his supporters hear that. And they're less likely to use mail balloting in places where there's an option to do so. So we're setting aside these all-mail ballots states. So we expect once we get to Election Day, these trends will generally hold.

START HERE: But in your mind, then, I mean, what is the probability in your mind that we have an answer on election night? And what what would throw that off?

MCDONALD: Well, I mean, it's difficult to say because we still have some more days of early voting to get through. I do expect some of the patterns that we've been seeing up to this point to shift some. And I would just say sit tight. I mean, we won't really know, at least in terms of the distribution of Democrats and Republicans who have voted early, until really this weekend. So I would just be cautious answering that question.

But let's put through some scenarios where, for example, if we're looking at ballots having to be counted, still mail ballots in places like Milwaukee or Philadelphia, we could be waiting a little bit deep into the evening when we're talking about hundreds of thousands of pieces of paper, envelopes that have to be opened and separated and identification checked over. So it just takes longer in those big cities.

START HERE: It sounds like maybe not even like hours like, could that be days in some areas?

MCDONALD: It has happened before that we've seen days. Arizona was a very good example of this in 2020, when Republicans who had mail ballots, but they were told "You better vote on Election Day." They held their mail ballots and dropped them off at the polling locations in Arizona, as is allowed under Arizona law. So Maricopa County, which is where Phoenix is located, was having to count ballots. And we knew that these were Republicans. They weren't Democrats.

And so actually, if anything, we were looking at a blue mirage in Arizona where Biden had a lead and Trump supporters were outside the convention center, the counting facility in Maricopa County, and they were chanting "Stop the count." Biden was actually leading. So then they had to change their chant to "Stop the steal," they figured it out after a day. Trump lawyers were on the inside. They were watching the count taking place and they needed those votes. So they were watching very carefully to make sure that they all would be counted correctly.

START HERE: All right. Strap in. Michael McDonald from the University of Florida. We'll check in with you after election night or election week or however long this ends up taking. Really appreciate your insight.

MCDONALD: You're welcome.