Dozens of lawmakers signed onto a request Tuesday for Attorney General Loretta Lynch to appoint a special counsel to oversee the investigation of Hillary Clinton's private emails.

Led by Rep. Ron DeSantis, who handed Lynch the letter during a House Judiciary Committee hearing, 44 Republicans questioned whether the probe of Clinton's emails was "politically impartial."

The lawmakers pointed to an Oct. 11 interview with President Obama in which he dismissed the notion that Clinton's private server risked national security.

"Given that the FBI has not finished its investigation regarding the use of Secretary Clinton's server, the president prejudged the outcome of the investigation," the 43 members wrote.

Sen. John Cornyn has led calls for a special counsel since September, but the Justice Department has been resistant to address critics of the investigation.

"It is critically important that this investigation is conducted impartially and that the decision to prosecute does not hinge on political considerations," DeSantis said Tuesday.

Supporters of the demand for a special counsel, an independent official to oversee the investigation, included Reps. Jim Jordan and Jeb Hensarling.

Lynch refused to answer questions during the Judiciary Committee hearing about when the Clinton email probe might wind down.

"I'm not able to comment on the status of that matter," she said. "It's impossible to predict when any matter will be concluded."

Earlier in the hearing, she dismissed suggestions that Obama's publicly-stated opinion would sway the FBI probe.

The investigation into Clinton's private server has reportedly expanded, even as the Democratic candidate herself claims victory over the email issue.

Clinton has attempted to link the House Select Committee on Benghazi's probe to the FBI investigation in an effort to downplay the latter. During the Democratic debate Saturday evening, Clinton touted the 11 hours she spent before the select committee in an answer to a question about the FBI investigation of her emails.

David Bossie, president of conservative watchdog Citizens United, was among the first to call on the Justice Department to appoint a special counsel.

"Democrat political appointees at the Justice Department cannot be expected to thoroughly investigate a person who may turn out to be the Democrat nominee for President of the United States," Bossie said Tuesday. "Furthermore, Attorney General Lynch has a personal conflict of interest in this matter since President Bill Clinton appointed her United States Attorney in 1999."