Washington (CNN) Senate Majority Leader Mitch McConnell said Wednesday that his chamber will work to replace Justice Anthony Kennedy before the midterms, a decision filled with political ramifications across Capitol Hill and the nation.

"We will vote to confirm Justice Kennedy's successor this fall," he said while speaking on the Senate floor immediately after the news.

But Senate Minority Leader Chuck Schumer made clear in a series of tweets, and on the floor, he wants to wait until after the midterm election, a precedent he says was originally set by McConnell in 2016.

"My @SenateGOP colleagues should follow the rule they set in 2016 not to consider a SCOTUS nominee in an election year. Sen McConnell would tell anyone who listened that the Senate had the right to advise & consent, & that was every bit as important as POTUS' right to nominate," he tweeted.

It's unclear what Democrats can do to stop Republican plans -- besides attempts to apply political pressure on the opposing party -- given the Senate rule change that allows Supreme Court justices to be approved by a simple majority. That means Democrats, who only control 49 seats in the chamber, may not be needed to advance the nomination.

Kennedy, who provided key votes for same-sex marriage, abortion access and affirmative action, had announced hours earlier Wednesday his plans to retire from the Supreme Court. The retirement is effective July 31, Kennedy said in a letter to President Donald Trump.

The weight of Kennedy's decision to step down is not lost on the senators, as the President's decision on a successor could transform the Supreme Court for generations.

The question emerging now in the Senate is whether Democrats will put up a fight to block the confirmation of a Trump nominated judge. Democratic senators signal the process to replace Kennedy might not be as easy as Republican leadership hope for it to be ahead of a midterm where a third of the Senate is up for re-election, though what specific steps they can take to halt the nomination remain unclear.

Republicans want such a vote now

Senate Judiciary Chairman Chuck Grassley, an Iowa Republican whose committee will handle the successor's confirmation hearing, praised Kennedy's legacy in a statement, also saying he expects the nomination process to begin "soon."

"For more than three decades, Justice Kennedy served with great distinction on the Supreme Court of the United States," he said in the statement. "I expect the President will soon nominate someone for the Senate to consider. I encourage the President to choose a nominee with the credentials, intellect and commitment to the rule of law necessary to serve on the Supreme Court."

He added: "I look forward to having the nominee before us in the Senate Judiciary Committee for his or her hearing in the weeks ahead."

Majority Whip John Cornyn, who learned the news from reporters at Capitol Hill, said the process of replacing Kennedy "energizes" conservatives.

"McConnell will make it a priority," he told reporters. "I think that's one thing (that) energizes conservatives more than anything else, is the Supreme Court."

He added: "My sense is we will be very busy after the President nominates his successor."

Fellow Texas Republican Sen. Ted Cruz called the moment to replace Kennedy an "opportunity" for Republicans, who have the majority in the Senate, to choose someone who represents their values.

"Justice Kennedy's retirement presents an opportunity for the President to appoint and the Senate to confirm a principled constitutionalist who will defend the Bill of Rights, defend the fundamental liberties of Americans, and I am hopeful that is exactly that will happen," he said. "I am confident we will take up and confirm the nominee this year before the election."

A Republican involved with Senate races says the Kennedy retirement is going to reshape the midterm dynamics by energizing conservatives and squeezing red-state Democrats, who will have to choose between a base that will want a big fight and more moderate voters. The source called the retirement "a majority saver."

In a rare hallway interview, Utah Republican Sen. Mike Lee told reporters that Kennedy's retirement is "big news" and as a lifelong watcher of the court, he's very interested in what comes next.

Asked if he'd be interested in the job, Lee noted that he "started watching Supreme Court arguments for fun when I was 10 years old."

If asked to consider it, Lee responded: "I would not say no."

Trump said he would select a replacement from the list of possible justices that he released during his campaign.

"We have a very excellent list of great, talented, highly educated, highly intelligent, hopefully tremendous people," he told reporters Wednesday after the news. "I think you see the kind of quality that we're looking at when we look at that list."

Democrats want to wait

Minority Whip Dick Durbin, an Illinois Democrat, said in a statement that McConnell set a standard in 2016 after the late Antonin Scalia's death that he wants to follow -- waiting until after a major election to decide on a replacement.

"Senator McConnell set the new standard by giving the American people their say in the upcoming election before Court vacancies are filled," he said in a statement. "With so much at stake for the people of our country, the US Senate must be consistent and consider the President's nominee once the new Congress is seated in January."

And he's not the only one. Sen. Dianne Feinstein, the top Democrat on the Judiciary Committee, agreed with leadership in a statement that there shouldn't be a vote on a replacement until after the midterms.

"We're now four months away from an election to determine the party that will control the Senate," she said in the statement. "There should be no consideration of a Supreme Court nominee until the American people have a chance to weigh in. Leader McConnell set that standard in 2016 when he denied Judge Garland a hearing for nearly a year, and the Senate should follow the McConnell Standard."

Besides Feinstein, Sens. Patty Murray, Mazie Hirono and Chris Murphy have said they hope for the same.

When asked about Democrats wanting to wait until after the election, Sen. Orrin Hatch, a Republican member of the Senate Judiciary Committee, said this year is different than an election year.

"I think we should just move ahead," he said. "That was a different situation ... it was close to a presidential election .. but this is not close (to a presidential election)."