WASHINGTON — When it came to filling a Supreme Court vacancy during the 2016 presidential election year, Senator Mitch McConnell had a constant refrain: Let the people decide. But should a high court seat become open in 2020, Mr. McConnell has already decided himself.
“Oh, we’d fill it,” Mr. McConnell, the Kentucky Republican and majority leader, gleefully told a friendly Chamber of Commerce audience back home in Paducah on Tuesday.
Mr. McConnell regularly celebrates his history-altering 2016 decision to thwart President Barack Obama from filling a vacancy that occurred with 11 months remaining in his term, saying the seat should be kept open until a new president could be elected and inaugurated. But he has been laying the groundwork to change course ever since Donald J. Trump was elected president. Tuesday’s remarks were only his most definitive: He would not be bound by the standard he himself set in preventing Judge Merrick B. Garland from being seated on the high court.
The comments immediately drew howls of blatant hypocrisy from Democrats and progressive allies. They said it underscored their view that Mr. McConnell was unprincipled and acted out of purely partisan motives in 2016 when he single-handedly decided to blockade Mr. Obama’s choice to replace Antonin Scalia after the court icon’s death that February.
“The bad faith behind McConnell’s position on Merrick Garland was obvious to anyone who was paying attention at the time and is a major reason why the public increasingly views the court as a partisan institution,” said Brian Fallon, who heads the progressive judicial advocacy group Demand Justice.
The declaration by Mr. McConnell suggests that the makeup of the Supreme Court will again be a central issue in the 2020 campaigns for the White House and the Senate, particularly with the intensifying fight over abortion rights. The Scalia vacancy was credited with significantly aiding Mr. Trump and cementing his support on the right in 2016. Democrats, stung by the 2016 loss and the failure to seat Judge Garland, have since tried to emphasize the political import of the Supreme Court to their voters through the emergence of groups like Mr. Fallon’s.
The distinction that Mr. McConnell and his allies draw is that in 2016, the process of filling the Supreme Court vacancy was split between Democrats who controlled the White House and Republicans who controlled the Senate. Voters had rendered a split decision, handing the executive to Mr. Obama in 2012 and the Senate to Mr. McConnell two years later, the majority leader argued; therefore, the tiebreaker would go to the winner of the 2016 campaign.
This is a line Mr. McConnell emphasized in October 2018 when he first began indicating that he was more than ready to take up a Trump nominee in 2020, should the chance arise.
“The tradition going back to the 1880s has been if a vacancy occurs in a presidential election year, and there is a different party in control of the Senate than the presidency, it is not filled,” he said.
But that was a nuance that Mr. McConnell and his allies stressed infrequently during the Garland blockade. They preferred a more straightforward message that a presidential election was approaching — was, in fact, underway through primaries — and that voters should determine who filled the seat.
“The American people should have a voice in the selection of their next Supreme Court justice,” Mr. McConnell announced in a stunning statement the evening of Justice Scalia’s death. “Therefore, this vacancy should not be filled until we have a new president.”
Mr. McConnell’s office on Wednesday circulated a memo showing instances when he mentioned the Senate-White House divide and said he was being consistent — an assertion Democrats ridiculed.
At least one influential Republican had earlier indicated that it would be wrong for Republicans to move forward with a nominee next year after their blockade of Mr. Obama even if Republicans controlled both the White House and Senate.
Senator Charles E. Grassley, the Iowa Republican who was chairman of the Judiciary Committee in 2016 and stood with Mr. McConnell against considering any Obama nominee, said last October that if he were chairman, he would not consider a Trump nominee in 2020.
“If I’m chairman, they won’t take it up,” Mr. Grassley said in an October 2018 interview on Fox News. “No, because I pledged that in 2016.”
But he added, “Now, if somebody else is the chairman of the committee, they’ll have to decide for themselves.”
Well, somebody else is the chairman: Senator Lindsey Graham, Republican of South Carolina and one of Mr. Trump’s most outspoken allies. He has made it abundantly clear that he intends to be highly aggressive in pushing Trump nominees to the court.
The most likely prospect for leaving the court voluntarily and creating an opening in the next two years would appear to be Clarence Thomas, 70, a justice since his bitter confirmation in 1991. Two of the other four conservatives — Justice Brett M. Kavanaugh and Justice Neil M. Gorsuch — just joined the court. The other two Republican appointees, Chief Justice John G. Roberts Jr. and Justice Samuel A. Alito Jr., are 64 and 69.
A decision by Mr. Thomas or another conservative to step down in the next two years would not change the ideological bent of the court, but it would allow the president to install a much younger conservative who could serve for decades more.
The four more liberal members of the court — Justices Ruth Bader Ginsburg, 86; Stephen G. Breyer, 80; Sonia Sotomayor, 64, and Elena Kagan, 59, would seem unlikely to give up their seats voluntarily when Mr. Trump and Mr. McConnell could engineer their replacements and further entrench conservatives.
A court fight during what is already anticipated to be a tumultuous Trump re-election campaign could energize both sides, and the temperature could be elevated even more by Democrats’ anger over what they see as flagrant hypocrisy by Mr. McConnell.
If Mr. McConnell forged ahead with a nominee in 2020, Democrats could do little to stop him. Rules changes since 2013 have eroded the power of the filibuster on nominations and left it strictly in the hands of the majority to push through nominees on the strength of 51 votes.
The problem for Mr. McConnell, who controls a Senate split 53 to 47, would be if even a handful of Republicans embraced the view expressed by Mr. Grassley last year that it would be improper to proceed with a nomination in a presidential election year after their own treatment of Mr. Obama and Judge Garland. In concert with Democrats, they could conceivably halt a third Trump nominee.
Such a divide among Republicans would probably be considered a surprise, given the hold Mr. Trump has on the party. What shouldn’t be a surprise is the declaration by Mr. McConnell that he would proceed with a nominee in 2020 despite his actions in 2016.