He speaks at March for Life, the nation's largest annual rally against abortion. She presented a landmark plan to protect abortion rights.

Vice President Mike Pence and Sen. Kamala Harris are set to face off on Wednesday in a debate bound to display their drastically opposing views on the issue, which takes on renewed urgency as the Senate considers the nomination of Amy Coney Barrett for the Supreme Court. Harris is in the unique position of being a sitting Senator who will decide Barrett's fate ahead of the election.

The two vice presidential candidates represent opposite sides of the spectrum on reproductive rights, as nationwide support for abortion rights remains high. A July 2019 ABC News/Washington Post poll found 60% of Americans say abortion should be legal in all or most cases, with only 24% saying abortion access should be harder.

A May 2020 poll by Gallup found similar results, with only 20% of respondents saying abortion should be illegal in all circumstances.

Read more on the candidates' positions on abortion here.

-ABC News' Alexandra Svokos

If Wednesday night showcases Sen. Kamala Harris the prosecutor, consider the new evidence added to her case.

And if Vice President Mike Pence is cast as the best explainer and defender of Trumpism, consider how much harder his job has become.

It's been eight short but incredibly long days since the first presidential debate. Since then, President Donald Trump has struggled to denounce white supremacism; refused to commit to accepting the results of the election; spread falsehoods about the voting process; been diagnosed with COVID-19, amid a full-fledged Washington outbreak; choreographed a triumphant return to the White House to urge the nation not to let the pandemic "dominate"; pulled the plug on further coronavirus relief talks until after the election and then reconsidered the move in some late-night tweets.

Enter the number twos -- in a campaign where there's seldom been more attention on the potential need for their services.

Pre-debate squabbles in Salt Lake City include fighting over plexiglass partitions and more space between the candidates to accommodate social distancing. What's really separating the vice-presidential candidates, though, are campaigns of the men at the top of the ticket -- who have distinct styles that are nothing like those of their running mates or each other.

Four years ago, it was Pence holding steady and calm in a debate with a feisty Sen. Tim Kaine, who faced blowback for his interruptions in a mild-mannered affair. Just last year, Harris' main debate opponent was the man she now shares a ticket with -- bringing set-piece attacks that appeared to nick former Vice President Joe Biden.

Now, amid the chaos of the moment and the relative stability of the campaign, Harris will bring a case that Pence might be uniquely equipped to defend.

-ABC News' Political Director Rick Klein

Sen. Harris underwent PCR testing for COVID-19 yesterday and COVID-19 was not detected, per a Harris aide.

-ABC News' Averi Harper

California Sen. Kamala Harris was selected as former Vice President Joe Biden's running mate on Aug. 11. She is the first woman of color on a major party's ticket, and if elected, she'd be the first woman and first woman of color to serve as vice president.

Her nomination came after serving as senator for California and as the state's attorney general -- and after her own, unsuccessful presidential nomination run. She suspended her presidential bid on Dec. 3, 2019 because, she wrote in an email to supporters, she didn't have the financial resources to continue.

Read more on Harris' background here.

-ABC News' Tessa Weinberg and Sruthi Palaniappan

PENCE'S CLAIM: "President Trump and I are fighting every day in courthouses to prevent Joe Biden and Kamala Harris from changing the rules and creating this universal mail-in voting that will create a massive opportunity for voter fraud."

FACT CHECK: Pence echoed Trump's attempts to cast doubt on the widespread embrace of vote-by-mail across the country this election by suggesting that universal mail-in voting could lead to massive fraud.

That is historically not true.

Kim Wyman, the Republican secretary of state in Washington -- a state that adopted statewide mail voting in 2011 -- told The New York Times in June that while any voting method could potentially be susceptible to fraud, in her experience as the chief elections official in the state, fraud with mail ballots is low.

"How do you respond to someone that makes an allegation that there's rampant fraud?" she said. "You show them all the security measures that are in place to prevent it and detect it if it does happen."

Ben Ginsberg, a Republican election guru who has spent years looking for voter fraud, wrote in a Washington Post op-ed, "Four decades of dedicated investigation have produced only isolated incidents of election fraud."

"These are painful conclusions for me to reach. Before retiring from law practice last month, I spent 38 years in the GOP's legal trenches. I was part of the 1990s redistricting that ended 40 years of Democratic control and brought 30 years of GOP successes in Congress and state legislatures. I played a central role in the 2000 Florida recount and several dozen Senate, House and state contests," he wrote. "The truth is that after decades of looking for illegal voting, there's no proof of widespread fraud."

Tom Ridge, a Republican who previously served as the governor of Pennsylvania and was the nation's first secretary of Homeland Security, previously told ABC News, "There is absolutely no antecedent, no factual basis for (President Donald Trump's) claim of massive fraud in mail voting."

--ABC News; Kendall Karson