Despite GOP control of Senate, Democrats promise SCOTUS fight ahead of midterms Democrats are highlighting abortion rights in their push-back.

On the issues of LGBTQ rights, abortion access, money in politics and the environment, no member of the federal judiciary has been more influential in the last 30 years than Supreme Court Justice Anthony Kennedy.

The announcement earlier this week of Kennedy's retirement sent political shock waves through both parties, and scrambled an already uncertain 2018 midterm landscape, as both parties gear up for what are sure to be contentious and complicated confirmation hearings for President Donald Trump's pick to take Kennedy's place.

But with the threshold for confirming the next Supreme Court nominee sitting at 51 votes, Democrats, in the minority, have little chance of blocking Trump's pick.

So many of them, including those thought to be eyeing presidential bids in 2020, are instead vociferously highlighting the issues Kennedy wrote about in the landmark cases in which he cast the deciding vote.

"This will not happen without a fight," New Jersey Sen. Cory Booker told a crowd gathered outside the Supreme Court Wednesday, "We who believe that a woman has the right to make her own medical decisions, we now must fight! Don’t tell me this battle is already lost — I don’t believe that."

"Women’s lives are at stake. I will fight for you to have a voice in the selection of our next Supreme Court justice, and I won’t ever stop fighting," New York Sen. Kirsten Gillibrand tweeted.

Gillibrand, Booker and other Democrats are trying to use the hashtag "DitchTheList" on social media to encourage President Trump not to choose a nominee from his list of potential Supreme Court nominees that was released last September.

California Sen. Kamala Harris explicitly called for the vote to fill the vacancy to be delayed until after the midterm elections.

"I know from personal experience — as a beneficiary of the landmark Brown v. Board ruling desegregating our nation’s schools — that decisions handed down by the court touch every aspect of our lives. The stakes don’t get any higher. Americans must be heard," Harris wrote in a statement released Wednesday.

Illinois Sen. Tammy Duckworth struck a similar tone to Harris, saying there is no need to "rush the process" with an election upcoming.

In a fundraising e-mail sent out this week, Wisconsin Democratic Sen. Tammy Baldwin, who is running for re-election this year, hit on abortion rights, same-sex marriage and health care as issues "on the line" in the choosing of the next person to sit on the nation's highest court.

"Roe v. Wade is on the line. Marriage equality is on the line. Pre-existing condition coverage is on the line," the campaign e-mail read.

On the campaign trail earlier this week in North Dakota, President Trump did not hesitate to cast Kennedy's retirement as an equally dire situation for Republican voters.

"Democrats want judges who will rewrite the Constitution, any way they want to do it, and take away your Second Amendment, erase your borders and throw open the jailhouse doors, and destroy your freedoms," Trump ominously claimed as he rallied supporters in Fargo, North Dakota for GOP U.S. Senate candidate Kevin Cramer, who is running against Democratic Sen. Heidi Heitkamp.

"We must elect more Republicans; we have to do that," Trump added.

In addition to being one of ten Democratic senators up for re-election this year in state's President Trump won in the 2016 election, Heitkamp in one of a cadre of Democrats the White House is hoping to woo in coming weeks as it relates to filling the Kennedy vacancy.

Heitkamp, Indiana's Joe Donelly and West Virginia's Joe Manchin all met with President Trump Thursday evening in an effort White House Press Secretary described as "part of ongoing outreach to get views and advice from both sides of the aisle."

All three of those Democratic senators present at the White House meeting voted to confirm Justice Neil Gorsuch, who filled the vacancy created by the death of Supreme Court Justice Antonin Scalia.

In a statement following the meeting, Heitkamp said she urged the President to pick a "non-ideological" judge to fill Kennedy's seat.

"I told the president that he has a chance to unite the country by nominating a true non-ideological jurist who could gain strong support from senators on both sides of the aisle, rather than create more divisions," Heitkamp said.

The jostling for votes all comes as Senate Majority Leader Mitch McConnell, R-Ky. is digging in on his position that President Trump's Supreme Court nominee should be confirmed before the midterm elections, which are now just over four months away.

McConnell was asked in a Fox News interview Thursday to respond to remarks made by Sen. Harris, who in addition to her official statement, said Trump's nominee would surely lead to the "destruction of the U.S. Constitution, we cannot relent on pushing back."

"It's pretty obvious they're ready to fight no matter who the nominee is," McConnell said.

Senate Minority Leader Chuck Schumer, D-N.Y. said Wednesday that it was the "height of hypocrisy" for McConnell to consider confirming a Supreme Court Justice in an election year considering that he did not allow a vote on President Obama's 2016 nominee to fill Scalia's seat, U.S. Circuit Judge Merrick Garland.

McConnell defended that position in the same Fox News interview, saying, "There's no presidential election this year," and pointing out that there are three current Supreme Court justices that were confirmed during a "non-presidential...election year."

Outside groups also gear up for SCOTUS fight

Advocacy groups on a host of issues important to Democratic voters are also signaling that they are ready for the upcoming confirmation fight, but few most have stopped short of calling for the vote to wait until after the midterms.

From abortion rights to environmental issues, to corporate money in politics, outside groups put the news of Kennedy's retirement in stark terms.

"Many Senators claim to support and protect the fundamental rights of women, but with a Supreme Court vacancy, a woman’s right to control her own destiny hangs in the balance," NARAL Pro-Choice America President Ilyse Hogue wrote in a statement Wednesday, "We were not fooled by then-nominee Neil Gorsuch’s claims at neutrality, and we won’t be fooled now. Our elected officials cannot wait days and weeks to show leadership; they must show leadership now."

League of Conservation Voters (LCV) President Gene Karpinski said the groups' two million members will be "out in force."

"The stakes for our environment, climate and democracy have never been higher, and our more than two million members will be out in force to ensure that Justice Kennedy’s successor upholds the values we share as a nation."

End Citizens United (ECU), a PAC that supports candidates who reject corporation donations, castigated Kennedy, who was the author of the Court's decision in Citizens United v. FEC,

"As the author of the Citizens United decision, Justice Kennedy opened the floodgates for unlimited, often anonymous, political donations and redefined public corruption, essentially selling our government to the highest bidders. His replacement could be the deciding vote in efforts to reverse that damage," ECU President Tiffany Muller wrote in a statement, "We need a justice who will side with the American people, who believes every vote counts, that there’s too much money in politics, and that government should serve the people -- not corporate special interests."

Lambda Legal, an American civil rights organization that focuses on lesbian, gay, bisexual, and transgender communities, scolded Kenndey over the timing of his retirement, and went further than other outside groups in saying that no Trump administration nominee should get a confirmation hearing until after the midterm elections.

"Not a single nominee by the Trump administration should get a hearing or a vote until after the November 2018 midterm elections," Rachel B. Tiven, Chief Executive Officer of Lambda Legal wrote in a statement, "Given everything happening in this country, and the fact that this President has worked to push through his own hateful agenda, the American people have a right to be heard before this critical decision."

In a sign that Republicans are very much aware of the potential electoral ramifications of allowing Democrats to capitalize on the vacancy as a way to energize their base, American Crossroads, a Super PAC with links to McConnell, placed a major ad buy in ten swing states advocating for the confirmation of a justice that will maintain the Court's rightward tilt.

"We think it’s important that as voters in various states, particularly the states where we’ve run these ads, that they start to focus on what’s at stake," American Crossroads President and CEO Steven Law said in an interview with NPR Friday, "It’s important that we continue the mainstream conservative jurisprudence that we’ve seen from the Supreme Court in recent in recent years."

The conservative Judicial Crisis Network (JCN) also launched a campaign this week to pressure vulnerable red-state Democrats into backing President Trump's eventual nominee.

"President Trump has proven that he wants the best of the best on the Supreme Court," the ad released by the group Wednesday says, "Now there's another opening, a chance to appoint another great justice."

The ad, showing pictures of liberal Senate Democrats, warns viewers not to be "fooled" by "extremists."

"Justice Kennedy was a transformative justice during a period of great transition on the Court, demonstrating the incredible impact one justice can have," JCN's chief policy counsel and policy director Carrie Severino said in a statement this week, "In cases like Obamacare, Heller, and Citizens United, Justice Kennedy was a passionate defender of individual liberty and the separation of powers. We thank him for his service to our country and we look forward to the nomination and confirmation of his successor."

ABC News' Meena Venkataramanan and Adia Robinson contributed to this story.