A document obtained from the Senate clerk shows which Republican senators switched their votes on the debt ceiling increase, apparently in an effort to force Republican leaders into action.

CW Roll Call

CQ Roll Call got the document, which shows that Senators Barrasso (Wyoming), Flake (Arizona), Hatch (Utah), McCain (Arizona), and Thune (South Dakota) all changed their votes on the motion to end a filibuster initiated by Republican Sen. Ted Cruz. So did Texas Sen. John Cornyn, but that's probably a different story.

As The Wire reported yesterday, Senate Minority Leader Mitch McConnell would have preferred not to vote for anything which could be spun by his conservative primary opponent as being supportive of an increase to the debt ceiling. While such an increase doesn't actually increase how much the government owes, it's generally perceived as giving the government more license to spend, which is anathema to conservative voters.

But Cruz's filibuster forced McConnell's hand. He and Cornyn, who serves as minority whip, apparently tried to get other Republicans to vote to end the filibuster. They declined, apparently demanding that the leadership go on record in support of the cloture motion first. Roll Call explains what happened next:

[S]everal of these senators had emerged together from the GOP Cloakroom to flip their votes at the same time, after Minority Leader Mitch McConnell of Kentucky and John Cornyn of Texas joined together to push the tally over the 60-vote threshold.

In other words: only once Cornyn and McConnell pledged to vote for the measure did the other five senators agree to do the same. The final vote was 67 to 31, with 60 votes needed to break the filibuster. The lesson in this is a simple one: politicians need political cover for votes. Sometimes that comes from obvious popular support. Sometimes it comes from making leaders walk the plank ahead of them.

We're learning what happened only after the fact, it's worth noting, which has made some reporters angry. As Politico reports, the usual practice is that the clerk announces votes as they happen — but that's not what happened.

The opaque proceedings prompted strong protests from the media’s governing bodies on Capitol Hill and demands for answers. NBC reporter Frank Thorp V, who chairs the Radio & Television Correspondents’ Association executive committee, called the clerk’s silence a “breach of decades of protocol.”

And the reason why was explicit, as Senate Majority Leader Harry Reid's spokesman told reporters afterward: it was done "to make it easier for Republican leaders to convince their members to switch their votes." In that sense, it worked like a charm.