Another court ruling has gone against allies of the Trump campaign in their bid to halt certification of the 2020 presidential election in Pennsylvania, as the state's Supreme Court issued an order Saturday dismissing a recent court challenge focused on mail-in voting.

This election challenge was brought by U.S. Rep. Mike Kelly, a Republican, along with another GOP candidate for Congress, alleging that the state legislature had not legally passed the measure allowing for universal mail-in voting.

The plaintiffs called on the court to have Pennsylvania Secretary of State Kathy Boockvar cancel all mail-in ballots or, if not, to empower the state legislature to appoint new electors. A trial judge on Tuesday had imposed a temporary injunction to pause the election certification process until the question could be resolved. Boockvar's office brought the matter immediately to the state Supreme Court.

The Pennsylvania Supreme Court vacated the injunction on Saturday and dismissed the case with prejudice, meaning the GOP cannot bring it back.

-ABC News' Matthew Mosk and Alex Hosenball

Biden and his transition team have announced three new members of their COVID-19 advisory board.  

After facing criticism for not having any current nurses on the advisory board, the new additions are Jane Hopkins, a registered nurse trained in mental health; Jill Jim, who is an enrolled member of the Navajo Nation and the executive director of the Navajo Nation Department of Health; and David Michaels, an epidemiologist and professor at George Washington University.

This brings the total number of members on the coronavirus advisory board to 16. 

“As COVID-19 surges across the country, I need a team advising me and a transition that offers diverse perspectives and viewpoints,” Biden wrote in a statement. “Ms. Hopkins, Dr. Jim, and Dr. Michaels will strengthen the board’s work and help ensure that our COVID-19 planning will address inequities in health outcomes and the workforce.”

The COVID-19 advisory board will help shape the approach to managing the current surge in coronavirus infections as well as ensuring an eventual vaccine is safe and effective, according to Biden’s transition team.

-ABC News’ Beatrice Peterson

Vice President-elect Kamala Harris, her husband Doug Emhoff and Washington D.C. Mayor Muriel Bowser visited a holiday market in the Penn Quarter neighborhood of D.C. for Small Business Saturday. 

Harris appeared to be wearing two masks and chatted with a couple of vendors, at one point stopping at a stand and holding up a T-shirt that read “Madam Vice President,” prompting the crowd to cheer.

Harris bought two puzzles at the New York Puzzle Company, which Emhoff paid for as the merchant took a photo of her through the plexiglass barrier.

At Marcella Kriebel Art and Illustration, she eyed a print of different types of coffee. Instead, she picked a print of different kinds of cheeses, while Emhoff bought the “Madam Vice President” T-shirt.

Harris stopped to greet shoppers before speaking with reporters. “We’re here with the great mayor of Washington DC, Muriel Bowser, to celebrate the small businesses that are here, but to celebrate small businesses all over our country. They’re suffering,” she said. 

“They are always really part of -- an essential part of the lifeblood of a community, part of the civic and social fabric of a community and, sadly, since COVID started, one in four small businesses in our country has closed,” she added. 

Biden tweeted Saturday, “Small businesses are the backbone of communities across the country — and amid the pandemic, they need our help more than ever. Today, and every day, support your neighbors and strengthen your community by shopping small. #SmallBusinessSaturday.” 

When asked about Trump and Vice President Pence not participating in the transition, Harris deflected and focused on how she and Biden are going to assist small-businesses during the pandemic. 

“We -- and the American people deserve that the incoming administration focuses on what’s important and what is important is getting a handle on this virus, opening back up our small businesses and -- and focusing on -- on the experts in all areas,” she said.

Harris was asked about reports that Trump has expressed a desire to run for president in 2024 and scoffed at the notion. 

“Please,” she said, laughing.

-ABC News’ Averi Harper

On Friday, more than 20 Republicans in the Pennsylvania House legislature introduced a resolution that disputes the statewide 2020 election results. 

With the Pennsylvania legislative session ending Monday, the move is likely to be vetoed by Democratic Gov Tom Wolf even if it were to move quickly through the state government.  

The resolution would also put the state’s Republican majority in jeopardy as it would threaten to invalidate the outcome of several GOP victories. 

Saturday morning, Pennsylvania state Sen. Doug Mastriano -- who Trump has taken to retweeting recently -- added to the state Republican voices attempting to challenge the outcome of the election in a series of tweets. Without citing any proof, Mastriano claimed, “there is mounting evidence that the PA presidential election was compromised.”

“If this is the case, under Article II, Section 1.2 of the US Constitution, the state legislature has the sole authority to direct the manner of selecting delegates to the Electoral College,” he said in one of his tweets. 

“Therefore, we are introducing a Resolution to exercise our obligation and authority to appoint delegates to the Electoral College,” he said. 

Twitter has stamped his tweets with, “This claim about election fraud is disputed.”

-ABC News’ Alisa Wiersema