WASHINGTON — (CNN) Democrats who have struggled to find a compelling message heading into the 2016 elections finally believe they have found something to latch onto: The Supreme Court vacancy.

Behind the scenes, the White House, congressional Democrats and the party’s political operatives are beginning to piece together an aggressive public-relations strategy aimed squarely at forcing Republicans to either acquiesce and give the nominee to replace the late Justice Antonin Scalia a confirmation vote — or suffer at the polls.

They are planning a range of efforts — from hardball tactics on the Senate floor to protests at Republicans candidates’ events back home — to paint the GOP as abdicating a central responsibility in Washington, according to party officials.

It’s a rare moment of unity for a party that has often been at odds over messaging and strategy, and seen their presumed presidential front-runner, Hillary Clinton, struggle in her party’s primary. But privately, Democrats say the GOP’s hardline against President Obama’s nominee — before one is even proposed — has become a gift for the party, giving them an issue they hope will galvanize their base and put vulnerable Senate Republican incumbents on the defensive.

“This has changed everything,” said one senior Democratic official.

Indeed, Democrats seem eager to seize the offensive, as Senate Republican leaders have been mostly quiet in the last couple days.

Senate Minority Leader Harry Reid wrote a blistering op-ed Tuesday in The Washington Post, calling the GOP “reckless.”

Obama, speaking to reporters in a news conference in California, didn’t mind speaking at length over the Republican tactics.

“I understand the stakes,” Obama said Tuesday. “I understand the pressure that Republican senators are undoubtedly under … And there are a lot of Republican senators who are going to be under a lot of pressure from various special interests and various constituencies and many of their voters to not let any nominee go through. No matter who I nominate. But that’s not the way the system is supposed to work.”

Republicans argue they are on firm ground to reject the nominee, believing that the Supreme Court is too important to leave to Obama. Moreover, they are certain that their own base will come out in droves to help re-elect a Senate majority if for nothing else than to prevent Democrats from tilting the court to the left.

But Republicans are not united about whether to prevent the nominee from having a committee hearing and a vote on the Senate floor over the nominee.

“2017 will be a chance to start over,” said South Carolina Sen. Lindsey Graham, a Republican who has backed the President’s last two Supreme Court nominees, but signaled there’s very little chance he’d do so now.

“If we lose the White House, and Hillary Clinton nominates someone to replace Scalia, I’ll vote for him,” Graham said.

But he added that he didn’t have much preference on whether to hold a hearing in the Senate Judiciary Committee and a vote on the Senate floor — and Utah Sen. Orrin Hatch told CNN he is “open” to holding hearings for the eventual nominees.

On Tuesday, Sen. Chuck Grassley, the committee’s chairman, would not rule out holding hearings. And his spokeswoman did not respond to multiple inquiries seeking additional comment.

Similarly, Mitch McConnell, the majority leader, has said little beyond a statement issued hours after Scalia’s death Saturday and right before the GOP presidential debate that night. Asked if McConnell was open to Judiciary Committee hearings, McConnell spokesman Don Stewart pointed to his statement from Saturday that didn’t address the issue directly.

“The American people should have a voice in the selection of their next Supreme Court justice,” McConnell said Saturday. “Therefore, this vacancy should not be filled until we have a new president.”

If McConnell takes a hard line and rules out floor votes on the nominee, there could be cracks in the GOP front. But if the GOP lets the nominee come forward, it could give momentum to Obama’s drive to add a liberal or moderate justice to replace the conservative Scalia.

On Monday, some Republican sources privately suggested that the Judiciary Committee could allow the vote to come forward and block the nomination in the panel by denying it from advancing on a party-line basis with their two-seat majority.

The two likeliest Republicans on the panel who would flip their votes are Graham and Arizona Sen. Jeff Flake, who is on official travel in Africa and has yet to comment on the matter.

On Tuesday, another Republican on the panel, freshman Thom Tillis of North Carolina, only seemed to give fodder to Democrats when he said on a radio program that the GOP shouldn’t fall into “the trap of being obstructionist.”

The Democratic strategy will roll out in earnest next week when lawmakers return to Capitol Hill and meet for the first time since Scalia’s death created a vacancy on the court.

But party officials say the Democratic echo chamber will be in full effect, through dilatory tactics on the Senate floor, speeches and protests around the country in states with vulnerable GOP senators, ample news conferences and potentially even a running clock showing the amount of time that has lapsed after the nominee is put forward.

The White House insists the process of selecting and nominating a person to replace Scalia shouldn’t become mired in partisanship, though the prospects of a landmark shift in the court’s political leanings have all but guaranteed a fight between Democrats and Republicans.

Obama’s aides began signaling their messaging strategy Monday, casting Republicans as shirking their constitutional duty and reiterating a longstanding argument that a GOP-controlled Congress has avoided taking any action on key issues.

The Democratic Senatorial Campaign Committee is already blasting out releases targeting vulnerable Republican senators in Pennsylvania, Illinois, Wisconsin and New Hampshire in an effort to push back against the GOP message that their party has got Congress “working again.”

And the effort also extends to the House. Democrats believe the issue is resonating beyond the handful of competitive Senate races. Even though House members don’t get to vote on any nomination to the high court, Democratic strategists think their candidates can replicate their leaders’ message, citing the GOP’s moves to block any nominee as part of their broader argument that Republicans are obstructing progress across the board in Washington.

At least 10 Democrats challenging GOP incumbents or running in open seats plan to highlight the issue this week, according to party officials.

Speaking at Stanford University Tuesday, House Minority Leader Nancy Pelosi said that the GOP was engaging in “pettiness.”

“It kind of begs the question — why this President, why this President should not be able to nominate, and they should not be able to consider,” she said.

But there are limits to the strategy.

Past White House attempts to goad lawmakers into taking votes on hot-button issues have produced mixed results, including in 2013 when the Senate rejected a bill to expand background checks for gun purchases despite a massive PR push by the White House in the aftermath of the Newtown, Connecticut, school shooting.

But Democratic officials believe that if the GOP takes a hardline and treats the nominee unfairly, it will prompt the kind of backlash the party suffered during the 16-day government shutdown in 2013.

A Democratic official said the White House strategy in pushing a nominee through the Senate will depend largely on whom Obama selects.

Many of Obama’s allies outside the White House are advocating a nominee who’s already been confirmed by the Senate, preferably in bipartisan fashion, to make Republicans appear politically driven if they refuse to consider the name for the Supreme Court.

Obama has also demonstrated a preference for naming Supreme Court “firsts” — he nominated the first Latina to the court in 2009 and has long expressed desire for court nominees who bring life experience to their judicial decisions.

Two of the names currently being floated — Attorney General Loretta Lynch and Federal Appeals Judge Sri Srinivasan — would fit that mold. Lynch would be the first African-American woman on the panel, and Srinivasan the first Indian-American justice. Both have been confirmed by the Senate, Srinivasan unanimously and Lynch, after a long delay, by a narrower margin.

Former Obama aides said they expected the President to move quickly to name a nominee, leaving little opening for the Senate Republican leadership to claim they weren’t allowed enough time to contemplate the pick.

That will also allow the White House to begin counting up the days that Senate Republicans fail to act on a nominee, a tactic they employed when Lynch was languishing after being tapped to serve as attorney general.

On Tuesday, Obama said his nomination would be announced in “due time.”

The-CNN-Wire ™ & © 2016 Cable News Network, Inc., a Time Warner Company. All rights reserved. (PHOTO: CNN)