IOWA CITY - Two federal judges from Iowa have announced plans to retire next year, and outgoing Democratic U.S. Sen. Tom Harkin is calling for the White House to appoint their replacements "as quickly as possible," his office said Monday. The planned retirements of U.S. District Judges Mark W. Bennett and James Gritzner give Harkin the chance to influence the selection of their replacements before he leaves office in January. The openings also give President Barack Obama a short window of time to get nominees confirmed while the Senate, where Republicans are trying to win back the majority in November, remains under Democratic control. Harkin said that he is recommending Obama appoint David O'Brien, a Cedar Rapids attorney and longtime Democratic Party activist, to replace Bennett. He said that he is asking Obama to replace Gritzner with either U.S. Attorney Nicholas Klinefeldt or veteran Polk County Judge Karen Romano. It's not clear when the White House will decide on the appointments. U.S. Sen. Charles Grassley, an Iowa Republican who is ranking member on the judiciary committee, could also have influence during the confirmation process. "This is the first we've heard of Senator Harkin's recommendations. Senator Grassley was not consulted," Grassley spokeswoman Beth Levine said. It is unusual for Iowa, a state that only has five active district judges, to have two pending vacancies for the lifetime judicial positions at the same time. Bennett informed Obama in January that he intends to retire July 4, 2015. A former civil rights attorney appointed by President Clinton in 1994, Bennett is known nationally as a critic of harsh sentencing policies for nonviolent drug offenders, his prolific writing on legal matters and his use of technology in the courtroom. He's overseen hundreds of jury trials in his courtroom in Sioux City.