Senate Majority Leader Mitch McConnell, R-Ky., is blocking a bipartisan effort to protect special counsel Robert Mueller's investigation of the Russia attack on the 2016 presidential election — prompting retiring Sen. Jeff Flake, R-Ariz., to pledge he'll block progress on confirming judicial nominees.

"Why are we so sanguine about this?" Flake said in a speech on the Senate floor Wednesday. "Why? Why do we do this, to protect a man who seemingly is so incurious about what Russia did during the 2016 elections. Why do we do that?"

Flake holds the deciding vote on a narrowly divided Senate Judiciary Committee, which means he could block forward movement on Republican-nominated judicial picks at the committee level for the rest of the year. There are currently 21 judicial nominees awaiting a vote by the Senate Judiciary Committee.

And in a Senate where Republicans hold just a two-vote margin over Democrats, if Flake can convince just one other GOP senator to join him, he could halt the confirmation of 32 judicial nominees now awaiting a vote on the floor.

The confirmation of judges has been a key agenda item for Republicans in the Senate. But McConnell objected to Flake's request for a vote on a bill intended to protect Mueller Wednesday afternoon, saying that he didn't see the probe as under threat.

"As you can imagine I talk to the president fairly often, [and there's been] no indication that the Mueller investigation will not be allowed to finish, and it should be allowed to finish," McConnell told reporters. "We know how the president feels about the Mueller investigation, but he's never said 'I want to shut it down'... I think it's in no danger so I don't think any legislation is necessary."

These latest developments come just a week after Attorney General Jeff Sessions was forced to resign and the president replaced him a man who has expressed skepticism of the ongoing probe.

Matthew Whitaker has previously advocated narrowing the scope of Mueller's probe or even limiting its funding.

"Jeff Sessions was just forced from office... [Whitaker] has already expressed hostility towards the investigation. I think that's a pretty good reason" to vote on the legislation, Flake said.

Flake, who is working on the legislation with Sen. Chris Coons, D-Del., is hardly the only Republican interested in protecting the ongoing Mueller probe.

"I think Mueller needs to be protected, and if something like [the Mueller protection bill] were to come to the floor, I can't imagine not voting for it," retiring Sen. Bob Corker, R-Tenn., the chairman of the Senate Foreign Relations Committee, told NPR.

"I believe that we should bring to the Senate floor legislation that would put restrictions on the ability of President Donald Trump to fire the Special Counsel," Sen. Susan Collins, R-Maine, said last week, after Sessions' firing.

The Mueller protection legislation would require that a special counsel only be fired for good cause, and would allow a special counsel to challenge his or her removal in the courts.

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