Pennsylvania, Texas, and Minnesota are setting aside some of their ballots in case a judge throws out the votes. Here's why.

• In Pennsylvania, Minnesota, and Harris Count, Texas, federal judges have ordered election officials to "segregate" certain ballots.
• For Pennsylvania and Minnesota, the vote-by-mail ballots that arrive after Election Day are being set aside in case another court invalidates them.
• In Texas, around 127,000 votes that were cast at drive-thru locations during the early voting period have been specially marked for the same reason.

In three states, election officials will "segregate" some of their ballots, setting them aside in case a federal judge later decides they should be thrown out.

In Pennsylvania and Minnesota, officials have been ordered to segregate ballots that arrive by mail after Election Day. In Harris County, Texas, the county clerk has been ordered to segregate the 127,000 votes cast at drive-thru polling places during the early voting period.

All of these court orders came after extensive litigation. But because they weren't totally resolved by Election Day, judges have asked election officials to mark the ballets in contention, in case a later court decision invalidates them.

It's not clear how many votes are at risk in Pennsylvania and Minnesota. After the judges issued rulings in each case, state officials and political parties launched information campaigns to dissuade people from continuing to vote by mail and choose other voting methods instead.

Why are these votes at risk? For different reasons.

In Pennsylvania's case, all eyes are on Amy Coney Barrett

Of all these cases, Pennsylvania's is the most closely watched.

The swing state has one of the tightest races in the nation. Joe Biden became the president-elect Friday morning after surpassing President Donald Trump by a few thousand votes, with ballots still being counted, according to Decision Desk HQ.

Like many states, Pennsylvania experienced a record level of voting by mail this year. President Donald Trump has followed through on his threats to litigate the election in the state, though most of his attempts have fallen flat.

Pennsylvania's Supreme Court approved an extension for mail-in ballots, allowing them to be counted even if they arrived up to three days after Election Day. It's a measure several states have taken in light of the coronavirus pandemic and postal service delays.

Republicans appealed the case to federal courts, arguing that only the state legislature — but not the state Supreme Court — could authorize such an extension. Their argument failed even when they brought the case to an appellate court.

When they appealed again to the US Supreme Court in late October, however, it was deadlocked at 4-4. The split decision defaulted to the ruling of the appeals court, which was a victory for voters and a loss for the Republicans who sought to block the extension.

However, with Justice Amy Coney Barrett now confirmed to the Supreme Court, Republicans are trying to get them to re-hear the case, hoping the Trump appointee will rule in their favor. The court refused a plea to hear it before Election Day but could still hear the case later.

Until then, Pennsylvania's Attorney General has asked county election officials to set aside ballots that arrived between 8 p.m. Tuesday and 5 p.m. Friday in case the Supreme Court re-hears the case and chooses to invalidate the ballots.

The total number of late-arriving ballots seem likely to number in the thousands, according to USA Today. It's highly unlikely that, even if they all went for Trump, they would swing the election.

Trump filed a motion Wednesday to join the Supreme Court case, though the Pennsylvania Democratic Party and Pennsylvania Secretary of State Kathy Boockvar have filed their own motions to block Trump and throw the whole case out. The Supreme Court hasn't yet signaled whether it will continue to hear the case, nor which parties would be allowed to participate.

Minnesota's probably won't matter for the presidential election, but they could be crucial down the ballot

Minnesota experienced similar circumstances as Pennsylvania. After a challenge from Republicans, a federal appeals court ruled that the state should set aside ballots that arrive in the mail after 8 p.m. on Election Day.

The appeals court ruling stopped short of determining whether those votes would be invalidated. With the lawsuit, state Republicans successfully fought another rule designed to protect voters in the coronavirus pandemic, which allowed election officials to count ballots postmarked by November 3 as long as they arrived by November 10.

In this case, the extension was set by Minnesota Secretary of State Steve Simon and approved by a state court. The Republicans argued that only the legislature could approve such an extension.

It's unclear what will happen to those ballots.

According to Simon, the ruling may only apply to votes for president, but not those in other races. But Biden handily won Minnesota. Simon also said he plans to count the votes unless one of the candidates successfully sues to invalidate them.

However, Simon acknowledged in a call with reporters, another judge may decide that other candidates have the standing to invalidate the ballots, which could be decisive in closer, down-ballot races.

North Carolina experienced similar legal challenges as Pennsylvania and Minnesota. But in that case, it was the state's board of elections that extended the mail-in ballot arrival deadline, rather than the state Supreme Court or Secretary of State. The US Supreme Court permitted the extension.

127,000 votes are in play in Texas

The Texas case also emerged from a pandemic-driven voting measure, but it has nothing to do with the mail.

In an effort to keep people safe, Harris County, the largest in the state, opened up 10 drive-thru polling places during the early voting period. The Houston Chronicle reported that 126,988 people voted at those sites, accounting for 9% of all early voting in the county.

Several Republican candidates and a right-wing radio host sued at the last minute, saying the drive-thru sites were not permitted without the approval of the Texas legislature. They argued that the ballots cast at those sites should be invalidated.

The all-Republican Texas Supreme Court rejected the lawsuit at a state level. On a federal level, the case was heard by Judge Andrew Hanen on Monday. He rejected the case, as well, saying the plaintiffs lacked standing to bring the lawsuit.

He also said that, even if they did have standing, he would still count the votes, but would not permit most of the drive-thru locations on Election Day, due to legal specifications for voting locations permitted during the early voting period, which are different from the specifications for locations on Election Day.

"To disenfranchise over 120,000 voters who voted as instructed the day before the scheduled election does not serve the public interest," Hanen wrote in his ruling.

Harris County Clerk Christopher Hollins closed all but one of the drive-thru voting sites for Election Day, worried that votes cast at those places would later be invalidated.

Hanen ordered Hollins to keep separate memory cards of all the votes cast at the drive-thru locations, in case an appeals court disagrees with him and decides to reject those ballots.

A panel of three judges on the Fifth Circuit Court of Appeals rejected a request to hear the case Monday night, according to court records reviewed by Insider. But the plaintiffs could appeal again, requesting that the full court take up their appeal.

Even if their appeal is successful, it's not clear that judges would rule to disqualify those votes. They may, as Hanen suggested in his decision, only rule on the legality of the voting sites, but not the votes cast at them.

• Read more:
• Trump keeps saying he'll sue for voter fraud, but he hasn't made that case in any of the 5 lawsuits he's filed
• Here are the legal challenges Trump's campaign has filed to dispute the 2020 election results
• How Trump's uphill legal battle against Biden over the election results could play out
• A federal judge threw out a Republican effort to invalidate 127,000 ballots cast at drive-thru voting locations in Texas
• 9 upcoming Supreme Court cases where Amy Coney Barrett could be the deciding vote