President Donald Trump last month tried to goad Sen. Chuck Grassley into ending the practice of giving deference to home-state senators in the judicial nominations process — a pressure campaign that quickly escalated into an all-out social media war on the 91-year-old Judiciary Committee chair.

“Senator Grassley must step up,” Trump said on Truth Social, noting that he got the Iowa Republican “re-elected to the U.S. Senate when he was down, by a lot.”

It didn’t work. Despite Trump’s threats to rally his base against Grassley, Senate Republicans rebuffed the attempts to get their colleague to give up on so-called blue slips, which allow members of the minority party power to effectively veto nominees for U.S. attorneys and district court judges who would serve their regions.

It also doesn’t look like their position will change heading into the fall, either, as Republicans have indicated they’ll seek a rules change to speed up the confirmation process for certain Trump nominees on the Senate floor but not at the committee level.

“As a practical matter, the Senate’s not going to give up the blue slip,” said Sen. John Kennedy (R-La.), a member of the Judiciary Committee, in an interview. “So my appeal to the president is: please reconsider. Why do we want to have this fight for nothing?”

It marks a rare instance where Hill Republicans have publicly broken with the president, underscoring how even Trump’s most loyal allies are willing to stand up to him when it comes to protecting their institution’s traditions — and their own ability to exert influence back home.

“The Senators have a real vested interest in what happens in their states,” said Mike Fragoso, a former chief counsel for nominations and constitutional law for the Senate Judiciary Committee. “At the end of the day, there’s probably very little support for what Trump wants within the conference.”

Fragoso, who also served as chief counsel for former Senate Republican Leader Mitch McConnell of Kentucky, argued that even Republicans wary of crossing the president now have taken advantage of the blue slip policy when Democrats held power. He added that there are relatively few bench seats in solidly Democratic states that Trump could even fill now without consent from Democrats.

Ultimately, said Fragoso, the blue slip’s elimination would just expose future seats in reliably red states like Florida and Texas to being filled with progressive judges by future Democratic administrations — and without the GOP getting much in return.

Grassley has also already made changes to the blue slip practice once, in 2017, when he announced he would move forward with circuit court nominees over home state senators’ objections. Although Judiciary chairs over the years had not always strictly followed that precedent, Grassley’s decision to consistently disregard it helped Trump see hundreds of judges confirmed during his first term in the White House.

It also helped to facilitate the recent confirmation of Emil Bove to the Third Circuit Court of Appeals over objections from New Jersey’s Democratic senators, Cory Booker and Andy Kim. As a senior Justice Department official, Bove was accused of recommending the administration defy court orders that would interfere with Trump’s immigration agenda.

But circuit court judges are different from district court judges: They have jurisdiction that extends beyond a senator’s state, while district judges and U.S. attorneys sit entirely within a given lawmaker’s home turf. And Republicans are finding themselves protective of maintaining control over these more localized positions as Trump is struggling to overcome Democratic roadblocks to confirming additional lower-level nominees.

Most recently, a court battle has broken out over Trump’s interim U.S. attorney for New Jersey, Alina Habba, after her temporary appointment expired and federal judges — not the president — installed a replacement. The Trump administration swiftly fired the court-selected pick and again appointed Habba, who Booker and Kim continue to oppose.

Senate Minority Leader Chuck Schumer is also leveraging the blue slip process by promising to withhold support for Jay Clayton to be the top federal prosecutor in the Southern District of New York — effectively blocking his confirmation.

Trump, losing patience, took to Truth Social in late July, calling in his post for Grassley to have the “Courage” to “step up” and abandon the blue slip “SCAM” as Democratic “SLEAZEBAGS … have an ironclad stoppage of Great Republican Candidates.”

He went on to repost a slew of messages from various users of the platform backing up Trump’s calls for a blue slip boycott and directing their ire at the longest-serving senator. One person argued that Grassley’s abandonment of the blue slip practice would be a fitting “Swan song” for his political career, with another calling Grassley a “RINO” — or, a “Republican in Name Only.”

Grassley, however, was unmoved.

“I was offended by what the President said,” he said in opening remarks at a Judiciary Committee hearing the morning after Trump’s initial post. “And I’m disappointed that it would result in personal insults.”

Grassley’s colleagues defended him, too, with Senate Majority Leader John Thune saying there simply was no appetite to change the practice on Capitol Hill.

But while Republicans continue to make the argument for keeping blue slips for political preservation purposes, others insist there will be political consequences for not eschewing the process.

Rob Luther, who was a top administration official involved in judicial confirmations during Trump’s first term, said he has long advocated for getting rid of the blue slip policy.

The conservative base, Luther explained, will soon get agitated by the outstanding number of bench vacancies that cannot be filled because of obstacles imposed by Democrats. That will especially be the case, Luther said, because there are so few openings — only about 50 free seats, according to the U.S. courts website.

“The district court blue slip issue is going to come up this term because there just aren’t enough vacancies,” Luther said. “It’s in Republican interest to get rid of the blue slips because we really need to get some solid conservatives in these deep blue states, and it’s the only way it’s ever going to happen.”

The blue slip practice also incentivizes senators to be uncooperative with their peers across the aisle, Luther said, recalling how there were significant vacancies on federal district courts during the first Trump administration because some progressive lawmakers from deep blue states were unwilling to make a deal on nominees.

Grassley seems to have anticipated this could become a liability for Republicans. Before he became the subject of Trump’s ire on the very subject, he began polling members of his committee to see if they’d support eliminating blue slips, Sen. Thom Tillis recently said on the Senate floor.

The North Carolina Republican — a member of the panel who is not seeking reelection — said he told Grassley that even if the policy were to be rescinded, he would continue to honor it anyway by opposing all relevant nominees who lacked support from their home state senators.

That stance would likely result in nominees being reported unfavorably out of the Judiciary Committee, setting up additional procedural roadblocks on the Senate floor — a counterintuitive outcome if eliminating blue slips was designed to clear the way.

In an interview, Tillis also warned of what would happen if Republicans changed the rules and then lost control of the Senate to Democrats: “It just means that you will not have any control when the roles are reversed.

“We can’t bow to pressure because of legitimate frustration in the moment,” he continued. “I get President Trump is frustrated. But I also understand, as somebody who’s spent 10 years in this institution and 10 years on Judiciary, it would be a bad idea. And he would even regret it.”