McConnell wants Supreme Court nominee vote by fall, Democrats say next year is fair "I'm worried about Roe v. Wade," said Democratic Sen. Jeff Merkley.

On the heels of Justice Anthony Kennedy's stunning retirement announcement, Senate Majority Leader Mitch McConnell stated flatly Wednesday that the Senate will vote on his replacement this fall.

"The Senate stands ready to fulfill its constitutional role by offering advice and consent on President Trump's nominee to fill this vacancy," McConnell said.

But the Senate's top Democrat is arguing Mitch McConnell should hold off on any confirmation vote until next year. To do otherwise, Chuck Schumer said, would be the "absolute height of hypocrisy."

Several GOP Senate seats are at stake in the midterm elections and Democrats hope to regain the majority.

"This is the most important Supreme Court vacancy for this country in at least a generation. Nothing less than the fate of our healthcare system, reproductive rights for women, and countless other protections for middle-class Americans are at stake," Schumer said.

"Millions of people are just months away from determining the senators who should vote to confirm or reject the president's nominee, and their voices deserve to be heard now as Leader McConnell thought they deserve to be heard then," Schumer went on, referring to President Barack Obama's nomination of Judge Merrick Garland in 2016.

McConnell refused to take up the Garland nomination, claiming it was too close to a presidential election and the American people should have a voice in the selection.

In a statement, Senate Judiciary Chairman Chuck Grassley, an Iowa Republican, said he "looks forward to having the nominee before us in the Senate Judiciary Committee for his or her hearing in the weeks ahead." The Senate Judiciary Committee conducts confirmation hearings for nominees.

Republicans were quick to heap praise on the retiring Kennedy and urged quick consideration of his successor.

“I would expect that the president would send us somebody who's well-qualified and we'll go about our business sooner rather than later, I hope,” Graham told reporters.

But Democrats are now increasingly concerned about the fate of the Supreme Court. When President Donald Trump nominated Neil Gorsuch last year, he tipped the balance in favor of conservatives.

Another conservative pick by the president is sure to be a blow to Democrats.

"This is a disaster for everyone who believes in the “We the People” vision of the Constitution," tweeted Sen. Jeff Merkley, D-Ore.

"I’m worried about Roe v. Wade," Merkley said in another tweet about the landmark decision in 1973 that recognized a woman's constitutional right to an abortion.

Sen. Richard Blumenthal, D-Conn., on Twitter seemed to sum up those broader concerns.

Other Democrats are urging McConnell to wait until after the midterm elections this fall because he blocked President Obama’s nomination in 2016, citing the need to wait until that year’s presidential election was decided.

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

“I hope Sen. McConnell follows his own advice, that in a decision this large that touches so many people that he allows the voters to weigh in,” Sen. Patty Murray, D-Wash., added.

When asked if he thinks it's fair to bring up a Supreme Court nominee during an election year, after blocking Obama's nomination of Garland in 2016, McConnell told reporters: "There's no presidential election this year."

ABC News' Trish Turner and Ali Rogin contributed to this report.