Sen. Lindsey Graham Lindsey Olin GrahamLive coverage: Barr faces grilling on Mueller's criticism The Hill's Morning Report - The heat turns up on Bill Barr Mueller fails to break stalemate on election meddling crackdown MORE (R-S.C.) reiterated on Wednesday that he will not ask special counsel Robert Mueller Robert (Bob) Swan MuellerSasse: US should applaud choice of Mueller to lead Russia probe MORE to testify about the Russia probe.

“I'm not going to do any more. Enough already. It's over,” Graham told reporters, asked why he wasn’t calling Mueller to appear before his committee.

Graham’s comments come after his panel held an hours-long, closely watched hearing with Attorney General William Barr William Pelham BarrMueller twice asked Barr to release report's key findings Read: Mueller's letter to Barr William Barr should be scrutinized on his record rather than rhetoric MORE about Mueller’s findings in the two-year probe on Russia's election interference and the Trump campaign.

Democrats — including Sen. Dianne Feinstein Dianne Emiel FeinsteinLive coverage: Barr faces grilling on Mueller's criticism Senate Dems put brakes on Trump impeachment talk California Democrats post tributes to former Rep. Ellen Tauscher MORE (Calif.), the top member of her party on the committee — are clamoring for Mueller to testify, arguing that Barr has misrepresented the findings of the Russia report.

Several senators have signaled they would be open to Mueller testifying. Sen. John Kennedy John Neely KennedyMORE (R-La.), a member of Graham’s committee, told reporters earlier Wednesday that he had “no problem” with Mueller testifying, wanting to know why he was “unhappy” with Barr.

Calls for Mueller to testify have also grown after reports emerged over the past 24 hours indicating that Mueller had expressed frustration to Barr about the attorney general's initial handling of the special counsel's report once it was filed in March.

Mueller twice asked Barr to release the special counsel's own summary of his findings from the 448-page report, according to a letter released Wednesday. Barr had initially summarized Mueller's findings in a four-page letter to Congress on March 24.

But top Republicans, including Graham and Majority Leader Mitch McConnell Addison (Mitch) Mitchell McConnellTop McConnell aide joins Chamber legal reform group Roy Moore 'seriously considering' another Senate bid McConnell: Changes to tax law to fund infrastructure a 'non-starter' MORE (Ky.), have indicated they think it's time to move on from Mueller.

"I appreciate very much what Mr. Mueller did for the country. I have read most of the report. For me, it is over," Graham said as part of his opening statement at Wednesday's hearing.