Senate Majority Leader Harry Reid (D-Nev.) is on track to set the record for having the best batting average when it comes to killing filibusters.

Since the beginning of the 111th Congress, Reid has won 90 percent of his efforts to cut off attempted Republican filibusters. Two former Majority Leaders — Bill Frist (R-Tenn.) and Mike Mansfield (D-Mont.) — tied for the next best record of winning votes to end debate or invoke cloture; both Senators prevailed 63 percent of the time in the 109th Congress and the 94th Congress, respectively.

If the Senate continues at its current pace, Reid will set a new record if he is able to win just one in five cloture votes for the rest of this Congress, a Roll Call analysis shows. Sixty votes are needed to beat back a filibuster and invoke cloture.

Reid spokeswoman Regan Lachapelle said Reid has succeeded despite what Democrats say is extraordinary GOP blocking tactics.

“We have done all of this with little or no help from Republicans who have chosen time and time again to do nothing,” Lachapelle said in an e-mail.

Though the repeated refusal of one or more Senate Republicans to allow Reid to bring up a bill or quickly close debate on legislation has been the primary reason for most of the 49 cloture votes during the 111th Congress, GOP votes have put Reid over the top in most cases. This Congress, Reid had a filibuster-proof, 60-vote majority for just six of the past 15 months. That was between the time Sen. Al Franken (D-Minn.) was sworn in last July and Sen. Scott Brown (R-Mass.) won the special election in January to replace the late Sen. Edward Kennedy (D).

One senior Senate GOP aide said the minority’s reluctance to move quickly on legislation isn’t necessarily about the policy itself; rather, it’s about Senators wanting to secure votes on their amendments.

“The fact that we’ve had so many cloture votes is not because legislation is not bipartisan,” the aide said. “It’s because there was a failure to negotiate a process to go forward.”

The aide added, “Winning cloture votes is sort of a dubious honor, because that means you had a partisan process to set things up.”

Though much was made of Brown’s status as the 41st Senate Republican who would give his party the ability to sustain filibuster, Reid has lost only one of the seven cloture votes held since Brown was seated, and Brown has been a frequent defector on those votes.

Reid is expected to win another cloture vote today — possibly with Brown’s help — when the Senate votes to close debate on an extension of jobless benefits.

“From a minority standpoint, you have to pick and choose your fights,” the senior Senate GOP aide said. “You can’t hold 41 on every vote that matters to someone. We have zero margin for error.”

The aide also acknowledged that only a handful of Senate Republicans have created the current climate of objecting to bringing up or closing debate on bills without a cloture vote, using the example of frequent objector, Sen. Tom Coburn (R-Okla.).

“There’s no question that Dr. Coburn wants everything to be paid for,” the aide said. “But that’s not a secret to anybody. They should be negotiating with him on the front end” to avoid filibuster fights.

Notably, when Mansfield set his record in 1976, cloture rules had just been altered to allow 60 votes — instead of 67 — to cut off debate on a bill, and Mansfield’s majority boasted 61 votes. Frist, on the other hand, set his record with only a 55-vote majority.

Eric Ueland, Frist’s former chief of staff, said Reid’s success can be attributed to several factors: that President Barack Obama hails from the same party, that Obama is in the first two years of his term and that Reid enjoys a robust majority.

“The data covers the initial two years of this administration, the time which history teaches gives a unified Senate/executive majority an extra boost due to the team-play spirit which predominates,” Ueland said. “This helps knock aside substantive and procedural obstacles to an agenda. [Reid’s] percentage also gets a lift because he hasn’t really slugged it out on highly controversial nominees — they were either marooned in committee or on the executive calendar or now, it appears, going to be recess-appointed.”

Though Democrats don’t discount that party unity is at an all-time high, they say they have the Republicans to thank for that.

One senior Senate Democratic aide said the minority has forced more cloture votes as more of a “stalling tactic” and the Democrats’ nearly unified stance has been a response to that. The aide added that while Reid struggled to corral all 60 Members of the Conference to vote for the controversial health care reform bill in December, most cloture votes have been on less controversial bills or nominations, on which it is easier to find unity.

“The ability to hang with your leader is dramatically increased” in those circumstances, the aide pointed out.

Since 1971, there has been a steady increase in the use of threatened filibusters and cloture motions by both parties. Last Congress, the Senate set an all-time record for most cloture votes with 112, but with only a 51-vote majority, Reid won 54 percent of the time. Prior to the 110th Congress, the record of cloture votes was only 61 — set during the 107th Congress, when control of the Senate switched from the Republicans to the Democrats in mid-2001.

“Cloture serves different purposes at different times for different leaders: for example, it can be primal scream therapy in a hopeless situation; a management tool to help demonstrate to all sides the need to move towards a policy end which is less than what the majority initially started off with; a political tool to help rally outside support; or the key moment to help pull enough folks together to push something through the floor,” Ueland said. “Given the immensely able work of Sen. [Mitch] McConnell’s [R-Ky.] team to challenge the Democrat majority at every turn, Sen. Reid has had to default to working overtime just to make absolutely sure he can pull something off before he ever starts it, which also contributes to his percentage so far this Congress.”