When the political mercenaries of American oligarchy jet off to consort with their electoral paymasters, they never imagine that the interactions will have consequences with constituents. The meetings are conducted in secret, the commitments that are made are never supposed to be revealed.

But, as Mitt Romney learned during the 2012 campaign, this is a new political era—when the old back-room banter about abandoning “the 47 percent” can go public and become the rallying cry for an opponent.

Senate minority leader Mitch McConnell was learning that Wednesday, as revelations about the top Republican’s pledges to serve the agenda of the billionaire Koch brothers came back to haunt him on the campaign trail in Kentucky. Within hours after the revelation of McConnell promising a room full of millionaires and billionaires that he would block minimum-wage increases, the extension of unemployment benefits and student-loan debt relief, his Democratic challenger was signaling that the senator would be held to account at home.

Kentucky Secretary of State Alison Lundergan Grimes, the Democratic candidate whose populist challenge has made McConnell’s re-election race a polling “toss up,” responded by linking the incumbent’s remarks at the secret session to those of Romney at a secret session in 2012. “I think Mitch McConnell got caught in his 47 percent Mitt Romney moment,” she told CNN. “I think it shows the extent and the lengths he will go to to pander to his party millionaires and billionaires at the expense of hurting Kentuckians.”

Conservatives on the campaign trail and in the media attempted to downplay the significance of the tape, suggesting that McConnell was simply restating his fierce opposition to initiatives that Democrats have advanced to aid working Americans. But the tape’s detailed discussion of using a Senate majority to prevent debate and votes on issues that polls say are of great concern to voters in Kentucky explained why it was being seen as a significant development by McConnell’s foes.

The Grimes campaign was already incorporating references to the tape into the campaign’s message, declaring that

Mitch McConnell revealed his true quest for power. In the secretive closed-door meeting with wealthy special interest backers, he outlined how he plans to hurt Kentucky families and pander to millionaires and billionaires. On issues like raising the minimum wage, extending unemployment insurance and helping Kentuckians with college affordability, McConnell promised his party’s rich backers that he stands with them, no matter the cost to Kentuckians and this nation.

It is no secret that McConnell is a faithful servant of the economic elites that fund his campaigns—that’s one of the primary reason he faces a tough re-election race this year—but he has historically tried to cloak the extent of his deference to the men who write all those checks to fund all those campaigns for McConnell and his preferred contenders.

Now the cloak is off. And the Grimes campaign is seizing on the opening, saying, “For the past 30 years, Kentuckians have questioned Mitch McConnell’s priorities, and now we have the hard evidence that his allegiances lie with his millionaire and billionaire donors at the expense of hardworking Kentuckians.”

The political fallout came amid widespread circulation of a tape of promises McConnell made to a California gathering of wealthy donors organized by Charles and David Koch.

The audio tape, which was obtained by The Nation and The Undercurrent, has been big news in Kentucky, where radio and television stations have aired the tape and newspapers featured headlines that included:

“McConnell ‘secret’ recording causes ruckus”

“McConnell vows to block minimum wage hike”

“Democrats pounce on recording of Mitch McConnell speaking at Koch brothers retreat”

The tape features McConnell announcing that “in the House and Senate, we own the budget. So what does that mean? That means that we can pass the spending bill. And I assure you that in the spending bill, we will be pushing back against this bureaucracy by doing what’s called placing riders in the bill. No money can be spent to do this or to do that. We’re going to go after them on healthcare, on financial services, on the Environmental Protection Agency, across the board.… All across the federal government, we’re going to go after it.”

In his remarks, McConnell griped about limits on campaign spending, hailed the US Supreme Court’s Citizens United ruling and encouraged his audience of millionaires and billionaires “to give to Americans for Prosperity”—the Koch-fueled political operation that has become a primary vehicle for aiding McConnell in his quest to become Senate majority leader.

The senior senator from Kentucky, who will take charge of the Senate if Republicans win control of the chamber this fall, left no doubt about what he would do as majority leader. After thanking Charles and David Koch personally and talking about how he and the other 1 percenters were “rallying, uh, to the cause,” McConnell pledged to use a Republican majority in the Senate to block progress on expanding healthcare, financial services reform and protecting the environment.

McConnell also promised to shut down debate on a host of economic issues, saying that “we’re not going to be debating all these gosh darn proposals…things like raising the minimum wage…extending unemployment benefits…student loan [relief].”

That, argues the Grimes campaign, “reveals the lengths Mitch McConnell will go to please his deep-pocketed donors.”

“Shockingly,” says Grimes aide Charly Norton, “Mitch McConnell will do and say anything it takes to secure his grip on personal power, including promising to hurt Kentuckians to benefit billionaires. Kentuckians who are struggling with unemployment, low wages and the soaring costs of higher education are the furthest thing from McConnell’s mind.”