The latest exchange happened Wednesday when Senate Democratic Leader Harry Reid blasted Chuck Grassley, the Republican chairman of the Senate Judiciary Committee, for his surprise attack a day
before on John Roberts, the conservative chief justice of the Supreme Court, who Grassley blamed for contributing to the politicization of the Supreme Court confirmation process.
"I'm here to defend Chief Justice John Roberts" who has been "attacked without cause," said Reid. In 2005, the Nevada Democrat voted against Roberts' confirmation.
"Senator Grassley has the audacity to accuse Roberts of being part of the problem, even going so far as to tell the chief justice: 'Physician, heal thyself,'" Reid said. "What needs mending is the Judiciary Committee under his chairmanship, which he has annexed as a political arm of the Republican leader's office. Senator Grassley has sacrificed the historical independence of the Judiciary Committee in order to do the bidding of the tea party and the Koch brothers," he said, referring to politically active billionaires David and Charles Koch.
The floor fight comes as the Senate is wrestling with President Barack Obama's nomination of Judge Merrick Garland, the chief judge of the U.S. Court of Appeals for the D.C. Circuit. Republicans, led by Grassley and Majority Leader Mitch McConnell, have vowed to block Garland so that a new president can pick someone to fill the high court vacancy, a defiant position that infuriates Democrats.
"The American people think it's political because the senior senator from Iowa is refusing to give a fair hearing to a highly qualified nominee because he was nominated by a Democrat," Reid said referring to Grassley.
At the White House, spokesman Josh Earnest called Grassley's criticism of Roberts "a pretty remarkable turn of events."
Grassley's speech was centered on comments Roberts made shortly before Associate Justice Antonin Scalia died in February suggesting the confirmation process had gotten too political and had poisoned the public's view of the Supreme Court.
"When you have a sharply political, divisive hearing process, it increases the danger that whoever comes out of it will be viewed in those terms," Roberts said at a forum at the New England School of Law in Boston. "It's natural for some member of the public to think you must be identified in a particular way as a result of that process. And that's just not how -- we don't work as Democrats or Republicans. I think it's a very unfortunate perception the public might get from the confirmation process."
Roberts, who was nominated by Republican President George W. Bush, has drawn fire from GOP presidential candidates Donald Trump and Sen. Ted Cruz of Texas -- and many other Republicans -- for upholding the President's Affordable Care Act, the health care law known as "Obamacare" that didn't get a single Republican vote when it passed.
Grassley, who voted in favor of Roberts' confirmation, alluded to that decision when he suggested the chief justice had decided the case based on his "policy preferences."
"The confirmation process has gotten political precisely because the court itself has drifted from the constitutional text and rendered decisions based instead on policy preferences ... the chief justice is part of the problem," Grassley said.
"He would be well served to address the reality, not the perception, that too often there is little difference between the actions of the court and the actions of the political branches," Grassley added. "So, physician, heal thyself."
Just as Republicans are blasting Roberts, the chief judge is also picking up support from Democrats.
Vice President Joe Biden, Justice Elena Kagan, a liberal who was nominated by Obama, and White House lawyer Neil Eggleston have come to Roberts' defense.
"Dysfunction and partisanship are bad enough on Capitol Hill," Biden said last month "We can't let the Senate spread that dysfunction to another branch of government -- to the Supreme Court of the United States. We must not let it fester."
Eggleston mentioned Roberts' comments during a talk hosted by Politico last week and added his own: "The more that that court becomes embroiled in our politics the less authority it has, " Eggleston said.
"I think one of the real tragedies of this entire process is the possibility that this contributes to a view that the Court is just another political organization," Eggleston added.
Kagan praised Roberts as a "consensus builder" who has worked to make the current 4-4 makeup of the court as "non-disruptive as possible."
Garland was back on Capitol Hill Wednesday meeting with a handful of Senate Democrats who are trying to pressure Republicans to act on the nomination.
Assistant Democratic Leader Dick Durbin of Illinois told reporters after his meeting with the judge that his party is "actively considering" using special procedural tactics to force a vote on Garland and that a decision will be made in the coming weeks whether to do so.
The number-two Republican, John Cornyn of Texas, dismissed the effort as "desperate" and said Democrats are "just trying to keep the buzz alive." He predicted any attempt to force a vote would fail to confirm Garland.
McConnell also reiterated this week he would not change his position on waiting until next year to confirm a justice selected by the next president.
Also Wednesday, CNN obtained a copy of a memo Sen. Mark Kirk, a vulnerable Republican running for re-election in Democratic-leaning Illinois, released to his GOP colleagues urging them meet with Garland. Kirk is one of only two Republicans calling for confirmation hearings and a vote on the nominee.
"We had a positive conversation," Kirk said about his meeting with Garland last week. "I encourage you to meet with him."