A new judge is poised to assume oversight of grand jury investigations concerning former President Donald Trump, including the ongoing probe into classified documents found at his Florida estate.U.S. District Judge James "Jeb" Boasberg is being sworn in Friday as chief judge of the federal district court in Washington, D.C. That role will give Boasberg, an appointee of former President Barack Obama, oversight of grand jury matters as well as sealed disputes that have surfaced in probes involving Trump.Boasberg is replacing the current chief judge, Beryl Howell, who is also an Obama appointee. Howell has served in the top job during numerous other high-profile investigations, including an earlier Justice Department investigation into links between Russia and Trump's 2016 presidential campaign. The chief judge position rotates on a seven-year basis.The position is important at a time when special counsel Jack Smith is conducting grand jury investigations into the retention by Trump of hundreds of classified documents at Mar-a-Lago, his Florida estate, as well as efforts by Trump and his allies to undo the results of the 2020 presidential election ahead of the Jan. 6, 2021 insurrection at the U.S. Capitol.The investigations have involved multiple sealed disputes, including a current fight over whether prosecutors can secure additional grand jury testimony from Trump lawyer M. Evan Corcoran. Corcoran last year drafted a statement saying that a "diligent search" for classified documents had been conducted at Mar-a-Lago, even though FBI agents weeks later searched the home with a warrant and found roughly 100 additional documents with classified markings.Corcoran had invoked attorney-client privilege during an appearance before the grand jury weeks ago. But Smith's team has sought to question him again by invoking an exception to attorney-client privilege. That dispute has played out behind closed doors, and it was not clear if it would be resolved before Boasberg took over as chief judge.Separately, former Vice President Mike Pence has said he will challenge a grand jury subpoena that seeks to compel him to testify in the special counsel's Jan 6. investigation. Pence has argued that because he was serving in his role as president of the Senate on Jan. 6, as he presided over a joint session of Congress to certify the election results, he is protected from being forced to address his actions under the Constitution's "speech-or-debate" clause that shields members of Congress.It is not clear how that disagreement will end.Boasberg has served as a federal bench in 2012. He also previously served as presiding judge of the Foreign Intelligence Surveillance Court, and in that role raised concerns to the FBI after a Justice Department watchdog report identified serious errors and omissions in surveillance applications filed during the Trump-Russia investigation.