Sen. Baucus says he was involved romantically with his nominee for Mont. post

Hanes, a former criminal prosecutor in Des Moines, divorced from her husband, former Iowa medical examiner Thomas Bennett, in December 2008. Hanes began working for Baucus during his 2002 reelection campaign and later became his state director and senior counsel, according to salary records compiled by LegiStorm. She is listed as a Baucus employee until March 31, 2009, and was paid $58,000 for her last six months working for him. She earned a salary of $127,000 in the previous year, records show.

Calling her "highly qualified," Baucus said that "I for one did not want her relationship with me to disqualify her from applying for the position" of U.S. attorney. He said he submitted six names to an unidentified "third-party reviewer," who winnowed the list down to Hanes, Bozeman attorney Mike Wheat and Helena attorney Michael W. Cotter. President Obama forwarded Cotter's name to the Senate in September.

Baucus said that "in the end, we decided it would be best for Mel to withdraw her name from consideration." He said Hanes applied for the Justice Department job independently and "got the DOJ job on her merit."

Justice Department spokeswoman Hannah August said Hanes was hired "because of her decades of experience in the field," citing her work as a leader in the 1990s prosecuting child abuse and neglect cases in Iowa, and in teaching and writing papers on the subject. "Her qualifications and experience made her an excellent candidate for the position, and she has proven to be a valuable member of the OJJDP team," August said.

Baucus was easily reelected in November, but polls show his popularity dropping this year as he assumed a prominent role in brokering controversial health-care legislation. David C.W. Parker, an assistant political science professor at Montana State University, said Baucus's recent approval rating of about 50 percent is "problematic" for a senator who has been in office since 1979. "If it persists, it will probably draw a competitive and quality challenger into the race in 2014," Parker said.

Staff writers Chris Cillizza, Shailagh Murray and Paul Kane and staff researcher Eddy Palanzo contributed to this report.