Supreme Court vacancy highlights stakes of presidential race for progressives

With President Donald Trump planning to name a Supreme Court nominee to replace the late Justice Ruth Bader Ginsburg next week, progressive and conservative groups are already gearing up to make the looming confirmation battle a top issue for voters in the November election.

On the left, as Joe Biden and other Democrats call for the Senate to keep Ginsburg's seat vacant for the next president to fill, activists have already started mobilizing voters around the possibility that a court with a 6-3 conservative majority could rule against pro-choice protections, the Affordable Care Act, voting rights and other key priorities -- and feature a Trump-selected nominee in the seat once held by a liberal legal icon for decades to come.

"It's not just a justice we lost, it's a giant," said Ilyse Hogue, the president of NARAL Pro-Choice America. "This sort of puts a laser-like focus on the enormity of this election."

Senate Majority Leader Mitch McConnell, R-Ky., has committed to holding a vote for Trump's nominee in the Senate, four years after he denied then-President Barack Obama a vote on Merrick Garland, his nominee to replace the late Justice Antonin Scalia, who died in February 2016.

"Since the 1880s, no Senate has confirmed an opposite-party president's Supreme Court nominee in a presidential election year," McConnell said in a statement Friday, explaining his 2016 position.

Republicans, with their 53-seat majority, can only afford to lose three votes -- with Vice President Mike Pence serving as a tiebreaker -- and still confirm Trump's nominee.

Sen. Susan Collins, R-Maine, who is up for reelection, said the vacancy should be filled by the winner of the next election, while Sen. Lisa Murkowski, R-Alaska, has previously said she would not fill a seat on the highest court so close to the election.

Senate Judiciary Committee Chairman Lindsey Graham, R-S.C., also supports moving forward with confirmation, though he opposed advancing Garland through the Senate in 2016.

With Trump trailing the Democratic presidential nominee in recent national and battleground state polls, some Republicans hope another Supreme Court vacancy will similarly clarify the stakes of the election on the right.

Four years ago, 70% of registered voters supporting Trump considered Supreme Court appointments "very important," compared to just 62% of Clinton supporters, according to a Pew survey.

"In 2016, we saw it bring people to the polls who may have had other qualms about aspects of the president's policies or personality, but who recognized that with the Supreme Court in the balance, that issue was incredibly important," Carrie Severino, president of the Judicial Crisis Network, a political organization that advocates for conservative judicial nominees, told ABC News. "It also has an encouragement, a get-out-the-vote effect."

"If it weren't for the Supreme Court, we wouldn't have President Trump today," said Severino, whose group is poised to play a key role in any campaign to promote Trump's nominee.

But there are signs that Democrats have started taking the issue more seriously: An August Pew survey found that 66% of registered voters supporting Joe Biden consider Supreme Court appointments "very important," compared to 61% of Trump voters.

Christopher Kang, the chief counsel of Demand Justice, a progressive group formed after the 2016 election to motivate liberals around the Supreme Court and judicial nominees, pointed to the polarizing confirmation process of Justice Brett Kavanaugh as a catalyst for an increased focus on the Supreme Court on the left.

"It's [Kavanaugh] and President Trump talking about the courts all the time, and the impact he's had," Kang told ABC News. "People are realizing, even if he's voted out of office in November, his judges are going to be with us for the next 30 or 40 years."

Demand Justice is planning a $10 million campaign against filling Ginsburg's seat before the inauguration -- one of several progressive groups gearing up to highlight the importance of the vacancy in both the presidential and down-ballot races in November.

The group is one of several progressive organizations calling for Democrats to eliminate the legislative filibuster and pack the Supreme Court with additional justices should Republicans fill Ginsburg's vacancy and Democrats retake the Senate and White House.

"The focus is on making clear what's at stake with this nomination and stopping this nomination," Kang said. "But I think part of that discussion is going to be, if we're not successful, and Republicans do ram through yet another Trump justice under a questionable confirmation process, what's going to happen next?"

The brewing political fight over Ginsburg's seat has also prompted an outpouring of cash on the left. ActBlue, the Democratic fundraising platform, reported raising $91.4 million in the 28 hours after Ginsburg's death, including a single-day record of $70.6 million on Saturday.

And another fundraising page from progressive site Crooked Media raised more than $17 million to split between 13 Democratic Senate campaigns.

"We're all mourning right now and we are coming together to honor and grieve Justice Ginsburg," Anisha Singh, the Director for Judiciary and Democracy Affairs for Planned Parenthood Action Fund, told ABC News, pointing to a rally the group organized for Saturday night outside the Supreme Court. "We also need to get back to work to preserve the ideals that she spent her life's work defending and make sure that we are in this fight, all the way."

ABC News' Meg Cunningham contributed to this report.