Democrats privately discussed their tactics during a closed-door retreat in West Virginia last week. And a number of Democrats are trying to persuade liberal firebrands to essentially let Republicans confirm Trump's pick after a vigorous confirmation process -- since Trump is likely to name a conservative to replace the late conservative Justice Antonin Scalia.
The reason for the tactic: Republicans are considering gutting the filibuster for Supreme Court nominees if Democrats stay largely united and block Trump's first pick. By employing the so-called "nuclear option," Senate Majority Leader Mitch McConnell could move to reduce the threshold for clearing a filibuster from 60 votes to 51 votes.
That would mean Democrats could lose leverage in the next Supreme Court fight if Trump were to replace a more liberal justice, since the GOP now has 52 seats in the Senate.
Preserving the filibuster now could give Democrats more leverage in the future, proponents of this strategy say. But it would enrage the Democratic base that wants a furious Democratic response to Trump's court pick.
Sen. Chris Coons, D-Delaware, a member of the Judiciary Committee told CNN he is still seething over the Republicans' decision to block Judge Merrick Garland from filling the seat when they refused to hold hearings and votes on his nomination last year.
"But I'm not going to do to President Trump's nominee what the Republicans in the Senate did to President Obama's," Coons said. "I will push for a hearing and I will push for a vote."
Other Democrats privately agreed with that sentiment.
Senate Minority Whip Dick Durbin, No. 2 in leadership, called the discussion "speculative."
Democrats are divided sharply on the question, which was a heavy focus of their legislative retreat in West Virginia last week and will be a top topic at their weekly policy lunch in the Capitol Tuesday.
Some liberals argue they should battle anyone who is nominated in retribution for the Republicans' handling of Garland, President Barack Obama's pick for the seat left vacant after the death of Justice Antonin Scalia almost a year ago.
Some of those Democrats believe they could block a nominee for up to a year, keeping the court divided 4-4 along ideological lines in the meantime. Vocal pressure from liberal voters could complicate any move to delay a Supreme Court fight.
"I support 60 votes," said Judiciary Committee member Sen. Amy Klobuchar, D-Minnesota, while acknowledging she doesn't know who will get tapped for the post. "Sixty votes is in the Senate rules and that is how we've done it and that's how we should do it."
But such a move is highly risky and could trigger a harsh response from the GOP.
Republicans could retaliate by using the so-called "nuclear option" to lower the threshold to break a filibuster of a Supreme Court pick from 60 to 51 and easily fill this vacancy and others to come. In 2013, Democrats used the nuclear option over the objection of Republicans when they lowered the threshold to break filibusters for executive branch appointments and all other judicial nominations except the Supreme Court.
Yet some Democrats who oppose putting off a fight on Trump's first Supreme Court nominee argue Republicans might not have the 51 votes they would need to approve the rules change, as some senior GOP senators may be reluctant to erode the effectiveness of the 60 vote filibuster, which famously preserves the power of the Senate minority.
Majority Leader Mitch McConnell, R-Kentucky, who opposed the Democrats' nuclear option, nevertheless has kept the option open for the Supreme Court. If Democrats were to successfully filibuster a Trump justice, the pressure from the right on McConnell could grow immensely.
"President Trump has a list of about 20 Americans who he is considering nominating to the Supreme Court. These men and women have different professional backgrounds, different life experiences," McConnell said on the floor, pleading with Democrats to confirm Trump's choice. "The Senate should respect the result of the election and treat this newly-elected President's nominee in the same way the nominees of other newly-elected Presidents have been treated -- and that is with careful consideration followed by an up-or-down vote."
In an early salvo on the issue, Democrat Sen. Jeff Merkley of Oregon, told Politico Monday he would filibuster virtually anyone Trump's selects for the court.
"This is a stolen seat. This is the first time a Senate majority has stolen a seat," Merkley said. "We will use every lever in our power to stop this."
One senior Democratic aide said Merkley' s announcement was expected and that just because he launches a filibuster, it doesn't mean he would have enough Democratic votes to support it especially if Democratic leaders decide it's smarter to save the fight for a future vacancy. Moreover, some moderate Democrats up for reelection in 2018 in states Trump won overwhelmingly could presumably break ranks and help the president get his pick confirmed.
Liberal firebrand Sen. Sherrod Brown, D-Ohio, said he wants to wait and see who the nominee is before deciding on a filibuster. Asked about Merkley's support for a filibuster, Brown replied, "that's his decision."
The decision for Democrats depends partly on who Trump names. If he picks a conservative that Democrats consider "mainstream" -- such as Appeals Court Judge Neil Gorsuch -- Democrats could hold off on a fight, according to the aides. But if he picks someone they consider outside the mainstream -- such as Appeals Court Judge William Pryor -- a major battle could ensue.