WASHINGTON — It’s an emerging rallying cry on the left: Expand the Supreme Court and eliminate the Senate filibuster.
Still seething over Republican obstruction during the Obama administration that peaked in 2016 with the blockade against the Supreme Court nominee Merrick B. Garland, liberal groups are encouraging Democrats running for president and the Senate to commit to enlarging the court and scuttling the Senate’s famous procedural weapon.
The intensifying push for those fundamental changes could add an explosive element to the 2020 campaign as candidates are forced to take a stand on structural changes in how government works. Multiple Democratic candidates have already said they would at least consider both possibilities, and activists intend to keep the pressure on to turn those proposals into top-tier issues.
“We cannot surrender to a status quo where Trump judges are set to block any solutions on health care, climate change or gun safety for the next 30 years,” said Brian Fallon, the head of Demand Justice, a liberal advocacy group focused on the federal judiciary. “The debate is quickly moving past the question of whether Democrats should seek to reform our courts at all to the question of exactly what type of reform to pursue.”
Ditching the filibuster and adding to the court to offset what many Democrats see as illegitimate conservative appointments by President Trump would probably have to occur in tandem if they were to occur at all.
Even if Democrats recaptured the White House and Senate while holding on to the House, Republicans — quite happy with the current makeup of the Supreme Court and hoping Mr. Trump can move it even further right — would almost certainly still have the votes to filibuster an expansion of the court. So Democratic activists who want to expand the court and push through other sweeping legislation say it would be time for the filibuster to go, too.
“We have to take back the Senate and ram a ton of big-time stuff through as fast as we can, and then face the voters with pride in what we’ve accomplished,” said Adam Jentleson, who was a top aide to Harry Reid when he was Senate Democratic leader.
It doesn’t always work out. The rush of legislation passed by strong Democratic majorities in 2009 and 2010, and signed by a Democratic president, Barack Obama, led to an enormous backlash in the 2010 midterm elections — even if much of that legislation is now popular.
And not all Democrats are ready to abolish the procedural tactic that allows the minority to tie up the majority legislatively if it cannot secure 60 votes. Far from it. Many Senate Democrats are still smarting after their 2013 rules change that weakened the filibuster against presidential nominees, opening the door for Mr. Trump to push conservatives onto the Supreme Court and the lower courts. They urge caution.
Senator Chris Coons, a Democrat of Delaware who was part of an unsuccessful 2017 effort to head off a Republican change that eliminated the 60-vote filibuster against Supreme Court nominees, said Democrats instead should focus on passing legislation with Republican help.
“The most important, the most significant, the longest pieces of reform in American history have been bipartisan,” Mr. Coons said in an interview. “We need to get back to passing meaningful legislation with bipartisan support.”
“Those who think it is a solution,” Mr. Coons said about eliminating the filibuster, “should spend some time serving in the House.” That was a pointed reference to the strong majority rule that exists across the Rotunda in the House, where the minority is often steamrollered and treated as irrelevant by the party in charge.
Both Mr. Coons and Senator Michael Bennet of Colorado, also part of the 2017 effort to preserve the Supreme Court filibuster, say that expanding the court will only add to the intensifying political aura around what is supposed to be a nonpartisan branch of government.
They say they recognize that Senate Republicans, led by Senator Mitch McConnell of Kentucky, the majority leader, have strong-armed two Trump appointees — Justices Neil M. Gorsuch and Brett M. Kavanaugh — onto the Supreme Court after blocking President Obama’s nomination of Judge Garland for almost a year. But they say that doesn’t mean Democrats should respond in kind.
“I know it is tempting to imagine everything we could do with 51 votes, but we also have a responsibility to consider everything Republicans could do and undo,” said Mr. Bennet, who is weighing his own run for the Democratic presidential nomination. “The lower-vote threshold has degraded the quality of judicial nominees and cabinet appointees — many of whom would never have been confirmed under the previous standard.”
Other Democrats worry the rising cry for structural changes such as ending the filibuster and eliminating the presidential Electoral College — another emerging theme — will allow Republicans to paint Democrats as a sore-loser party that pushes to change the rules when it cannot win elections. They fear it will turn off voters leery of tinkering too much with the United States’ governing institutions.
Republicans moved quickly to respond.
Senator Marco Rubio, Republican of Florida, called this week for a constitutional amendment that fixes the membership of the Supreme Court at nine and drew strong Republican support.
“The Democrats’ court-packing proposal represents the latest shortsighted effort to undermine America’s confidence in our institutions and our democracy,” Mr. Rubio said.
Senator Marsha Blackburn, a freshman Republican from Tennessee, said there was “no plausible reason to add more justices other than for Democrats to add judges who will legislate from the bench and further policies that failed to pass through Congress.”
Mr. Trump repeatedly agitated for eliminating the filibuster in his first two years in office, when Senate Democrats stymied him even though Republicans controlled the House and Senate. That push seems to have died down now that Democrats control the House. In the past, Mr. Trump also backed electing presidents through the popular vote, but he has changed positions after losing the popular vote and winning the Electoral College in 2016.
Despite pushback by Republicans and some Democrats, the discussion about sweeping institutional changes is only increasing on the left and will no doubt be a central element of the Democratic primary debate given deep frustration among activists. David Axelrod, the former top political strategist for Mr. Obama, said he believed “Democratic primary candidates are fishing in a promising pond” when it came to the filibuster and court issues.
“There is a sense that the filibuster, once an extraordinary tool, has become so commonplace as to make a mockery of majority rule,” Mr. Axelrod said. “And McConnell’s yearlong roadblock of the Garland nomination has heightened a feeling that the court has been packed.”
Political process arguments are usually seen as the fallback for someone losing the main fight. But in this election cycle, where Democratic candidates fall on the political process argument might instead be a key to winning.