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 pivoted from a question on pre-existing conditions to press Harris for an answer on whether or not she and Biden supported adding additional seats to the Supreme Court.

"I think the American people would really like to know, if Judge Amy Coney Barrett is confirmed to the Supreme Court of the United States, are you and Joe Biden, if somehow you win this election, going to pack the Supreme Court to get your way?" the vice president asked.

Harris used her first answer to attack the Trump administration for rushing a vote on Barrett's nomination by bringing up a Republican the president often compares himself to -- Abraham Lincoln.

"It was 27 days before the election, and a seat became open on the United States court. Abraham Lincoln's party was in charge of not only the White House but the Senate," she said, referring to the 1864 election.

"But Honest Abe said it's not the right thing to do," Harris added. "The American people deserve to make the decision about who will be the next president of the United States, and then that person can select who will serve for a lifetime on the highest court of our land. And so, Joe and I are very clear: the American people are voting right now, and it should be their decision about who will serve on this most important body for a lifetime."

MORE: Most say wait on Ginsburg seat, while opposing packing the court: Poll

Pence used her non-answer to say that Biden and Harris would pack the Supreme Court and that he and Trump would protect the current number of justices on the court. 
"The American people deserve a straight answer," he said. "And if you have not figured it out yet, the straight answer is they are going to pack the Supreme Court, if they somehow win this election.

Harris responded that Republican efforts to get more conservatives confirmed as federal judges amounted to packing the court, noting that of the 50 people the president nominated to the Court of Appeals none were Black. She did not state her position on adding seats to the U.S. Supreme Court.