During a congressional showdown over illegal immigration last spring, Justice Department officials found themselves scrambling to answer Republicans’ pointed questions about low immigration-related prosecution rates by U.S. attorneys on the southwest border. Republicans, including Rep. Darrell Issa, R-Calif., had homed in on Southern California’s U.S. Attorney Carol Lam, demanding to know why they were hearing she had refused to prosecute illegal immigrants unless they had previously been convicted of two felonies.

Internal e-mails released as a part of a congressional investigation show Justice Department officials conceded among themselves that they had “some concerns about asserting that the SO Cal U.S. attorney’s office has a strong record in this area.” The e-mail exchange – between Associate Deputy Attorney General Lee Otis and other Justice officials in April 2006 – is one of several contained in more than 3,000 pages of documents released over the past week. The newest batch, released Wednesday, includes further references to intense criticism from Republican lawmakers about the priorities of several border-state U.S. attorneys. Just months later, Lam, Arizona’s Paul Charlton and New Mexico’s David Iglesias were among eight U.S. attorneys abruptly fired with no explanation.

The dismissals have caused an uproar on Capitol Hill as lawmakers have demanded to know whether they were part of a purge to replace the prosecutors with political cronies or as a result of their work on political corruption cases. All three border prosecutors were investigating political corruption cases at the time they were fired.

Justice Department officials said after the firings that poor performance and policy disputes were behind their decision. Immigration-related prosecutions were at least part of their concerns with Lam, Charlton and Iglesias, Justice Department officials have said, although officials have also said they had other problems with each. Department spokesman Brian Roehrkasse said Wednesday that “consistency with the department’s policy priorities” on immigration was “an appropriate factor that (it) considered in deciding to ask for the resignations of U.S. attorneys.”

The border-state U.S. attorneys were scrutinized at a difficult time for the Bush administration. The president was struggling to get wary House Republicans to back his immigration plan, which called for a guest worker program for foreigners and a path to citizenship for illegal immigrants in the country now. Many Republican lawmakers were calling for a border fence and tough restrictions on illegal immigrants.

The U.S. attorneys on the southern border prosecuted more than two-thirds of the criminal immigration cases in the nation in 2005. But lawmakers repeatedly questioned their priorities. Even Sen. Dianne Feinstein, D-Calif., now one of Lam’s strongest supporters, questioned Lam’s immigration prosecution rates, although Feinstein said she was satisfied with the answer that Lam was focusing on big cases.

Issa and 18 other lawmakers angrily wrote Attorney General Alberto Gonzales on Oct. 20, 2005, about immigration prosecutions, particularly in Southern California. “It is the responsibility of the Department of Justice to punish dangerous criminals who violate federal laws, and this includes criminal aliens,” the letter reads. Republican Sen. Pete Domenici called Gonzales in January 2006 to discuss the “criminal docket and caseload” in his home state of New Mexico. Domenici’s call prompted a flurry of questions about how the caseload in New Mexico compared with other states. A memo from the U.S. attorney’s executive office quotes Iglesias as saying there was a severe need for more prosecutors in the border city of Las Cruces. Justice Department officials later listed poor morale and insufficient resources in Las Cruces among their concerns about Iglesias’ management.

And in a July 2006 meeting with Bush, then-Speaker Dennis Hastert, R-Ill., raised concerns about Charlton’s policy of prosecuting only cases charging possession of more than 500 pounds of marijuana. At the time, the Justice Department defended Charlton and his colleagues. Federal prosecutors’ resources on the southwest border – particularly Arizona – were “absolutely stretched to the limit,” wrote Rachel Brand, an assistant attorney general, in an e-mail to Gonzales’ chief of staff, Kyle Sampson, who recently resigned. Less than two months later, Charlton was on the list of federal prosecutors the attorney general’s office and the White House were considering pushing out.