Minnesota Secretary of State Steve Simon said Friday that his office will not challenge an appellate court decision that requires the state to separate any mailed-in ballots received after the polls close on Election Day.

"We disagree with the court's decision, and there may be cause for litigation later," said Simon, who added that his office's focus will be on making sure voters cast ballots by the 8 p.m. Election Day deadline.

Simon, and other elected officials and activists alike, spent Friday urging voters to return absentee ballots in person or elect to vote in person instead of mailing in their ballots. They are concerned about an Eighth U.S. Circuit Court of Appeals decision Thursday ordering all ballots received after Tuesday's 8 p.m. deadline to be segregated in response to a lawsuit from two GOP presidential electors. Simon and political party leaders worry that future legal challenges could invalidate ballots in the hotly contested election.

"We need to emphasize that there is no court ruling yet saying those ballots are invalid," Simon said. "We absolutely reserve the right to make every argument after Election Day that protects voters."

Election officials in Minnesota and across the nation have faced an onslaught of legal challenges this election season, mainly targeting new rules aimed at making voting easier during the pandemic.

Simon's office said Friday that nearly 2 million Minnesota voters had requested absentee ballots for the general election. Of that total, more than 388,000 ballots had yet to be returned to county election officials.

Simon agreed to a seven-day extension for accepting ballots earlier this year after a citizens group pressed the issue in state court. The group feared that the pandemic and ensuing mail ballot surge would lead to delays in getting absentee ballots returned on time. Ballots still must be postmarked by Election Day to be counted. GOP challengers pointed out that the change Simon agreed to let ballots without postmark dates be counted unless a "preponderance of the evidence" proved they were mailed after Nov. 3.

Meanwhile on Friday, a group of conservative political activists challenging the state's requirement that voters wear masks at polling places made a last-ditch appeal to the U.S. Supreme Court. The latest appeal came just four days before Election Day.

Attorneys for the Minnesota Voters Alliance filed a 70-page emergency application to the high court after a federal judge in Minnesota refused to overturn the requirement earlier this month. The Eighth Circuit denied a similar motion earlier this week, leading to Friday's appeal to Justice Neil Gorsuch.

Erick Kaardal, an attorney for the alliance, said Friday that they have yet to learn whether the Supreme Court would take up their case.

The Minnesota Voters Alliance is arguing that by wearing masks to the polls, voters could be subject to penalties for violating a 1920s-era law against disguises in public places initially enacted over concerns about the Ku Klux Klan's rise.

U.S. District Judge Patrick Schiltz, in an order this month that declined to block the mask mandate at polling places, wrote that accepting that argument could lead to "absurd results" such as first responders being barred from wearing surgical masks while tending to injured people on public roads, or government workers being forbidden from wearing protective suits to clean up hazardous material spills. Schiltz also concluded that the group had "no chance of success" in its claim that DFL Gov. Tim Walz's emergency order violated the First Amendment.

In his petition to the U.S. Supreme Court, Kaardal is seeking an emergency order overturning the mask mandate before Election Day while the lawsuit challenging the merits of the requirement continues in the courts. Absent that, Kaardal wrote, the alliance and five individual activists named as plaintiffs will not be able to vote on Election Day "without threat of criminal and civil prosecution."

Solicitor General Liz Kramer, in a briefing to the Eighth U.S. Circuit Court of Appeals this month, defended the mask mandate as being "thoughtfully conceived by public health professionals to address the specific and deadly exigencies posed by the public health crisis facing our state."