President Donald Trump vowed to sue over a Senate practice that allows a lawmaker to block his U.S. attorney and district court nominees, as the top Republican on the Senate Judiciary Committee stood firm against doing away with the tradition.Trump homed in on the "blue slip" tradition in the Senate, which effectively gives Senate Republicans and Democrats the ability to veto district court and U.S. attorney nominees in their home states. His desire to see the practice done away with comes as Senate Democrats have stood in the way of his nominees making their way through the upper chamber in a speedy fashion.TRUMP TELLS GRASSLEY TO TELL DEMOCRATS 'GO TO HELL' OVER BLOCKED JUDICIAL NOMINEES IN SENATE"Were also going to be filing a lawsuit on blue slipping," Trump told reporters in the Oval Office on Monday. "You know, blue slips make it impossible for me, as president, to appoint a judge or a U.S. attorney because they have a gentlemans agreement. Nothing memorialized. Its a gentlemans agreement thats about 100 years old, where if you have a president, like a Republican, and if you have a Democrat senator, that senator can stop you from appointing a judge or a U.S. attorney, in particular, those two."His decision to turn to the courts also comes after he targeted Senate Judiciary Chair Chuck Grassley, R-Iowa, over the weekend. He again demanded that Grassley do away with the practice.But over multiple posts on X on Monday, Grassley argued that without blue slips, none of Trumps nominees would pass muster in the Senate."A U.S. Atty/district judge nominee without a blue slip does not [have] the votes to get confirmed on the Senate floor & they dont [have] the votes to get out of [committee]," Grassley said. "As chairman I set [President] Trump noms up for SUCCESS NOT FAILURE."Trump argued that it was his constitutional right to appoint judges and U.S. attorneys, but the right had been "completely taken away from me in States that have just one Democrat United States Senator."GRASSLEY REBUKES TRUMP'S PRESSURE TO 'HAVE THE COURAGE' TO SPEED UP NOMINATIONS"This is because of an old and outdated custom known as a BLUE SLIP, that Senator Chuck Grassley, of the Great State of Iowa, refuses to overturn, even though the Democrats, including Crooked Joe Biden (Twice!), have done so on numerous occasions," Trump said. "Therefore, the only candidates that I can get confirmed for these most important positions are, believe it or not, Democrats! Chuck Grassley should allow strong Republican candidates to ascend to these very vital and powerful roles, and tell the Democrats, as they often tell us, to go to HELL," he continued.TRUMP TELLS SCHUMER TO 'GO TO HELL' OVER SENATE NOMINEE DEAL FUNDING DEMANDS AFTER NEGOTIATIONS COLLAPSEBut Grassley countered that the tool was just as important for Republicans, particularly during the Biden administration, to ensure that Trump had more vacancies to fill when he took office."The 100-year-old 'blue slip' allows home state senators 2 [have] input on US [attorneys] & district court judges," Grassley said. "In Biden admin, Republicans kept 30 LIBERALS OFF BENCH THAT PRES TRUMP CAN NOW FILL [WITH] CONSERVATIVES."Senate Democrats have indeed used the blue slip tradition since Trump took office for his second term to block some of his picks as part of their broader log jam of his nominees.For example, Senate Minority Leader Chuck Schumer, D-N.Y., used his blue slip privileges to nix Trump's U.S. Attorney nominees for the Southern and Eastern Districts of New York.And Sens. Cory Booker and Andy Kim, both Democrats from New Jersey, used the blue slip to object to Alina Habba's nomination to U.S. Attorney in the Garden State. Habba was tapped by Trump to serve in the role on an interim basis, but after her term expired, a panel of judges opted to not extend her position.A replacement was chosen but then fired by Attorney General Pam Bondi. Trump then withdrew his nomination for Habba and restored her interim status."Habba was withdrawn as the President's nominee for New Jersey U.S. Atty on July 24," Grassley said. "[And] the [Judiciary Committee] never received any of the paperwork needed for the Senate to vet her nomination."Trumps renewed ire comes after he singled out Grassley last month for not nixing the longstanding tradition, which is not a law, and demanded that he "have the courage" to change the practice.It also comes after Senate Republicans and Democrats failed to reach a deal on ramming through many of the presidents nominees before leaving Washington for all of August.Finding a pathway forward, including a likely change to the Senates confirmation process, is expected to be a top priority for Republicans when they return to the Hill after Labor Day.