Partisan warfare is erupting in the Benghazi committee as Hillary Clinton prepares to testify

In a series of increasingly nasty press releases, interviews, and open letters, partisan warfare is erupting on the House Select Committee on Benghazi.

The tensions come as former Secretary of State Hillary Clinton, the Democratic presidential front-runner, is set to testify before the committee on Thursday.

On Monday, the committee's Democratic members released a 124-page report arguing that the Republican-led effort is wasting taxpayer funds in order to try and tank Clinton's White House bid.

The committee's top Democrat, Rep. Elijah Cummings (D-Maryland) said in a statement accompanying the report that it's "time to bring this taxpayer-funded fishing expedition to an end."

"Republicans have now admitted repeatedly that they are spending millions of taxpayer dollars to damage Secretary Clinton's campaign for president," he said. "This report shows that no witnesses we interviewed substantiated these wild Republican conspiracy theories about Secretary Clinton and Benghazi."

The Republican majority on the committee fired back at the report with a feisty statement of its own.

"Why is every single bullet point in the Democrats' press release about Clinton and not a single one about the four people who were killed or about providing better security in the future?" committee spokesman Jamal Ware asked Monday. "This is further proof of the Democrats' obsession with covering for Hillary Clinton instead of investigating the Benghazi terrorist attacks."

Some of the fiercest shots have been exchanged between Cummings and Rep. Trey Gowdy (R-South Carolina), who chairs the select committee. On Sunday, the two traded passive-aggressive letters accusing each other of politicizing the committee, which is investigating the deadly September 11, 2012, attacks on a diplomatic compound in Benghazi, Libya. Clinton was secretary of state at the time.

Cummings attacked the credibility of the Republican-led committee in his letter. He said the CIA had informed the panel that it did not view an email forwarded by Clinton in 2011 to include any classified information. Gowdy had used the email as an example of what he suggested was a mishandling of information on the private server.

"On October 7, 2015, you sent me a 13-page letter making a grave new accusation against former Secretary of State Hillary Clinton. Specifically, you accused her of compromising national security and endangering lives," Cummings wrote.

"The problem with your accusation-as with so many others during this investigation-is that you failed to check your facts before you made it, and the CIA has now informed the Select Committee that you were wrong. I believe your accusations were irresponsible, and I believe you owe the Secretary an immediate apology."

Gowdy responded with a letter of his own disputing Cummings' claims.

"Thank you for your early Sunday morning letter. I appreciate the opportunity to respond," Gowdy wrote to Cummings. "As usual, I would ask you to completely and accurately relate the facts rather than attempt to create an impression that is misleading based on an incomplete and selective recitation of the facts."

Gowdy included an addendum dripping with sarcasm, as well:

PS: I am envious of your staff's ability to get information from this administration in less than 45 minutes on a weekend. This is something the majority Members struggle to do on weekdays. Perhaps you would be willing to help us gain access to the information the Committee has been seeking from the administration for over half a year now.

The Benghazi committee has been in the spotlight for its role in highlighting Clinton's controversial email practices as secretary of state. Clinton exclusively used a personal email server for her State Department work, and the FBI is investigating whether any classified material was mishandled in connection to the account.

Democrats - including Clinton herself - pounced when House Majority Leader Kevin McCarthy (R-California), who was then expected to be the next House speaker, bragged at the end of last month that the Benghazi committee helped bring down Clinton's poll numbers.

McCarthy attempted to walk back the comment, but for Democrats, it was a pivotal moment that revealed the committee's true intentions. A flood of Democratic statements have since blasted the Benghazi investigation as a partisan sham.

Rep. Richard Hanna (R-New York), a relatively moderate Republican, added more fuel to the fire last week when he speculated that the committee was indeed going after Clinton.

"This may not be politically correct, but I think that there was a big part of this investigation that was designed to go after people and an individual, Hillary Clinton," Hanna said.

A visibly frustrated Gowdy addressed the criticism Sunday on CBS' "Face the Nation." He stressed that neither McCarthy nor Hanna is especially familiar with the committee's work.

"I get that there is a presidential campaign going on. I have told my own Republican colleagues and friends, 'Shut up talking about things that you don't know anything about,'" Gowdy said. "And unless you're on the committee, you have no idea what we've done, why we've done it, and what new facts we have found."