As President Trump and Senate Republican leaders plan to push through a new Supreme Court justice before the election to replace Ruth Bader Ginsburg, they also have a Senate majority to worry about protecting.

Republicans are playing defense in about two dozen seats, and about a dozen are shaping up to be competitive. A number of these races are in more conservative states, but Democrats have room to work with. To take back the majority, Democrats need to net at least three Senate seats and win the White House so the vice president can cast the tie-breaking vote.

Before Ginsburg’s death, neither side could predict with certainty which party would win the majority in November. That remains true immediately afterward. But both sides see reason to be optimistic that the coming political battle can give them a boost on the ballot — Republicans with their base voters specifically, and Democrats with more swingy independent voters. Let’s look at how.

Republicans hope this will bring back in GOP voters disaffected by Trump’s coronavirus response

One of the main reasons so many Senate seats are competitive for Democrats is because Trump’s handling of the pandemic is dragging down Republican candidates. Two back-to-back Quinnipiac University polls have shown Sen. Lindsey O. Graham (R) in South Carolina, where voters are meh on Trump’s coronavirus response, tied with his Democratic challenger, Jaime Harrison.

But in the week before Ginsburg’s death, Republican strategists told The Fix that they were seeing early signs some of those Republican voters were coming back home to their political party, as these voters start contemplating whether they would actually vote for a Democrat and decide maybe they don’t want to.

Could a Supreme Court fight help accelerate that trend and protect Republican seats? Two GOP strategists think so. Conservative voters, motivated by antiabortion causes, have typically been more animated about Supreme Court battles than moderate or liberal voters.

Trump and this Republican Senate have steadily moved the court to the right with two hard-fought new justices. Now they have a chance to put an exclamation mark on it by replacing one of the court’s most reliably liberal voters with a conservative one and reshape the Supreme Court to be conservative for a generation, one that could knock down long-standing abortion or gun-control laws.

“This is going to be quite helpful clarifying the stakes for Republican voters,” said one Republican working on Senate races, who spoke on the condition of anonymity to discuss strategy. “It shifts focus onto more of a straight partisan issue that we know animates Republican voters and should juice our base."

That of course will also help Trump, since some of the biggest Senate battles are also taking places in states he’s trying to win, like Arizona and North Carolina.

“This is a big political gift basket for Trump in that it super motivates his GOP base, changes the subject from the coronavirus and puts the Biden campaign on the defense, making it more of a choice election,” said Scott Reed, political strategist for the U.S. Chamber of Commerce, which is focused this cycle on keeping Republican control of the Senate.

Democrats hope they can make vulnerable Republicans look like they’re catering to Trump

The potential risk for Republicans is that as they rally their base, they risk alienating moderate voters. Putting a new justice on the court two months before a presidential election after many of these same Republicans argued four years ago that election-year confirmations are wrong is blatantly political, no matter how Senate Majority Mitch McConnell (R-Ky.) tries to frame it. That’s where Democrats hope they can seize the narrative.

Trump still isn’t popular in the races that could decide the Senate majority — in Colorado and Maine, he’s downright unpopular. So Senate Democrats have spent months trying to tie GOP senators to the president. Already, potentially vulnerable Republican senators like Joni Ernst in Iowa, Martha McSally in Arizona and Thom Tillis in North Carolina have signaled they’re okay with an election-year justice. Democrats think that plays right into their hands.

“This really reinforces a core argument that the incumbents are caving to Trump,” said one Democratic strategist who spoke on the condition of anonymity to discuss internal strategy, “and that they’re not doing what’s right. They’re not an independent voice for their states.”

When it comes to messaging issues before the court, Democrats are focused on health care. They have been campaigning for several election cycles now that they are the party that wants to protect Americans’ coverage for preexisting conditions. Conveniently for them, the Supreme Court is scheduled to hear a case that could destroy the Affordable Care Act — with the Trump administration’s blessing — just after the election. That gives them plenty to talk about.

“Our number one goal must be to communicate the stakes of this Supreme Court fight to the American people,” Senate Democratic leader Charles E. Schumer (D-N.Y.) told his colleagues on a call Saturday, according to a individual on the call.

Nowhere is all this more resonant than in Maine. Sen. Susan Collins (R) is running for reelection in a state that doesn’t approve of Trump. She’s down 12 points in a recent Quinnipiac University poll to her Democratic challenger, Maine Speaker of the House Sara Gideon, who is arguing Collins is an ineffective critic of the president. Collins is often a swing vote in these Supreme Court fights. Maine is also a state that broadly doesn’t approve of abortion restrictions, yet Democrats are pointing out that Collins has supported numerous federal judges whose views on abortion are more conservative.

Democrats think this all makes her particularly vulnerable, even more so than she looked before Friday.

On Saturday, Collins issued a statement in which she tried to appease both sides. She said she thinks the candidate who wins the November election should get to nominate the next justice but said “she would have no objection” to the Senate starting the process and considering Trump’s nominee.

The huge caveat to all this is that, for now, this is just educated speculation. It’s possible this all evens out, and we’re right back where we started, unsure which party will have the Senate majority in 2021. After Senate Republicans muscled Justice Brett M. Kavanaugh onto the court just before the 2018 midterms, results were mixed on which party benefited politically from that fight.

Michael Scherer and Seung Min Kim contributed to this report.