With Congress stuck in a bitter dispute over fiscal matters, there seemed to be no good solution for Senator Mitch McConnell of Kentucky, the Republican leader up for re-election next year. Forge a compromise and risk attack from a primary opponent on the right. Block a deal and give fodder to a general election opponent on the left.

By stepping in after two weeks of a government shutdown, but right before a potential default, Mr. McConnell ensured he would be attacked from both sides.

For the most part, the responses from back home have been predictable – the campaign of Alison Lundergan Grimes, the Democratic candidate for his seat, said Mr. McConnell “hid in the shadows,” for weeks, while Matt Bevin, his Tea Party-backed primary opponent, said Mr. McConnell had “cut and run from yet another fight.”

But the heat has also come from outside the state: a conservative group assailing him for an issue that seems almost anachronistic — earmarks.

The Senate Conservatives Fund is calling it “the Kentucky Kickback”: a $2.8 billion authorization – an increase from an earlier allotment – for the Olmsted Locks and Dam project in the western part of the state.

“In exchange for funding Obamacare and raising the debt limit, Mitch McConnell secured a $2 billion Kentucky kickback,” said Matt Hoskins, the executive director of the group, which is affiliated with former Senator Jim DeMint.

Mr. Hoskins directly tied the Kentucky Kickback to the so-called Cornhusker Kickback, $100 million in extra Medicaid funding for Nebraska to get Senator Ben Nelson’s support for the health care overhaul. (The measure was ultimately eliminated before passage.)

But in this case, the request for the Kentucky measure actually came from Tennessee and California.

Senator Lamar Alexander, Republican of Tennessee, said he and Senator Dianne Feinstein, a California Democrat, asked that the authorization for the Olmsted project be included to avoid losing $160 million in canceled contracts.

“It’s the biggest lock in the country, and I’m not going to stand around and see $160 million wasted,” Mr. Alexander said on Wednesday. The project, which has been approved by both the House and Senate before, would replace existing locks and dams near the confluence of the Mississippi and Ohio Rivers, affecting Illinois, Tennessee and Kentucky.

In an interview on Thursday with the talk radio station WVLK, Mr. McConnell dismissed the idea that the authorization was an earmark, saying that the Army Corps of Engineers had requested the money and that other senators had been able to review the deal and none asked for it to be removed.

“If he didn’t want the earmark included, he could have kept it out,” Mr. Hoskins said in the statement.

The dispute reflects a broader cultural change in Congress: Mr. McConnell is trying to deflect responsibility for financing a project that will most likely bring jobs and improve trade in his region. In the more recent past, a top spokesman for Mr. McConnell called the Olmsted Dam “a top infrastructure priority for Kentucky” in an August interview with James Bruggers of The Courier-Journal of Louisville.

Dam earmark or none, Mr. McConnell might be unable to prevent another torrent from rolling into his state. In a Facebook message on Wednesday night, Sarah Palin announced that Kentucky would be her next target.

But he is focused on a message that is very different from hers. As part of a series of interviews on Thursday, Mr. McConnell told The Courier-Journal, “I’ve demonstrated again within the last 24 hours that when the country needs an outcome, I’m the person who can negotiate with the other side.”



Jonathan Weisman contributed reporting.