As the story goes, when President Franklin D. Roosevelt in 1942 asked Sen. Kenneth McKellar, then the ranking member of the Appropriations Committee, to quietly provide $2 billion for a secret weapons lab, the Tennessee Democrat had a brief and quick response.

“Mr. President, I have just one question. Where in Tennessee do you want me to hide it?” McKellar said, according to congressional lore about Tennessee’s Oak Ridge National Laboratory, a key part of the Manhattan Project.

It was just one instance among countless cases on Capitol Hill where appropriators — the lawmakers who hold the prized positions closest to the federal purse — found a pressing national priority fitting in neatly with local interests for economic development and the jobs that come with it.

From the funds longtime appropriator John P. Murtha, a Democrat, funneled to his hometown of Johnstown, Pa., by locating the National Drug Intelligence Center there to the federal dollars Harold Rogers, a Republican and now the House Appropriations chairman, steered toward the anti-drug nonprofit Operation Unite, which he helped found in his southern Kentucky district, the appropriations story has been one of political clout executed through the federal spending process.

That’s why legislators such as McKellar and Murtha would have been shocked at the decision Sen. Sherrod Brown, D-Ohio, made at the start of the 113th Congress, when he gave up the chance to move up the seniority ladder on Appropriations for a seat on the tax-writing Finance Committee.

At the same time, two senior Democrats — Tom Harkin of Iowa and Patrick J. Leahy of Vermont — passed on the chance in December to take over the gavel after the death of Daniel K. Inouye of Hawaii, leaving more junior Barbara A. Mikulski of Maryland to become chairwoman.

In the House, Cynthia M. Lummis, R-Wyo., left Appropriations after one term, shifting to a Natural Resources Committee she said was more suited to the needs of her state. Lummis had previously said she didn’t enjoy her time on Appropriations.

“Clearly, one would have to say that the committee is at a low ebb,” said former Appropriations Chairman Robert L. Livingston, a Louisiana Republican who led the panel during its last intense period of budget cutting in the 1990s. “It’s a sign of the times.”

For today’s legislators, the appropriations assignment simply is not what it used to be.

The Republican ban on earmarks has undermined the ability of appropriators to mete out money to their own congressional districts and win favors by sending funds to other districts. The cardinals, as subcommittee chairmen are often called because of their sway, now are expected to sing along with the rest of the choir.

Instead of gaining favor with constituents, lobbyists and fellow members through their ability to direct federal spending, members of the Appropriations committees are being “squeezed like we’ve never been squeezed before,” Rogers said last month. Rogers has helped slash more than $40 billion from the federal government’s annual operating expenses since becoming chairman in 2011, and more programs will take hits in the years ahead.

But congressional insiders say the diminishing appeal of appropriations goes beyond the tighter purse strings. The annual spending bills for federal agencies are seen as prime vehicles for directing federal policies, but that power is diminished as a Congress in gridlock opts for extensions over bigger, and more contentious, legislation.

Congress hasn’t passed real appropriations bills for three years, and the sort of continuing resolution that is funding the government this year is typical, extending programs based on last year’s spending levels and offering only a handful of policy directions.

The trend goes beyond appropriations, experts say. In recent years, much of the power in Congress has been consolidated in the hands of a few members, a tight circle of those in leadership, said Livingston, leaving big committees such as Agriculture and Transportation and Infrastructure unable to score legislative wins with multiyear measures.

Appropriators, with a mandate to move a dozen annual spending bills, stand out as particularly vivid examples of the weakening of committee power, he said.

Preferring HELP

The three Democrats who recently passed on Appropriations pointed to their specific long-term interests as the drivers of their decisions — not a diminished appeal for appropriations.

Brown sees taxes, federal health care policy and foreign-trade debates, which will affect Ohio’s manufacturers, as his greatest concerns.

Leahy says his “passion” for the issues facing him as chairman of the Judiciary Committee led him to reject the Appropriations gavel, and Harkin preferred the Health, Education, Labor and Pensions Committee over a post that, after all, could not hand out earmarks.

“I suppose that had something to do it,” Harkin said of the earmark ban. “But, quite frankly, I love the HELP committee. I love the issues that we are involved in.”

Appropriations committees in both chambers still attract recruits, and there’s been no noticeable plunge in contributions to top appropriators since the earmark ban went into effect.

Two former governors joined the Senate Appropriations Committee in the 113th Congress — Democrat Jeanne Shaheen of New Hampshire and Republican Mike Johanns of Nebraska. And Democrat Jeff Merkley of Oregon, who early in his career worked at the Congressional Budget Office, said he started looking for an Appropriations seat even while first talking with Democratic leaders about possibly running for the Senate.

“There’s a host of issues where it is helpful to bring the perspectives of your particular economy, your particular geography, your particular citizens to the discussions about where we should spend dollars,” Merkley said.

Senators had a better chance than most rank-and-file House members to influence appropriations in the 112th Congress, despite more floor time given to spending bills in the House.

In both years of that Congress, House Republicans moved about half of the annual dozen spending bills under spending caps that reflected the desire of conservatives to cut spending. There was virtually no chance of getting Senate Democrats or the Obama administration to agree to these levels, making the House-passed versions of spending bills little more than political exercises.

After Congress reached accord on a fiscal 2012 cap on discretionary spending in August 2011, appropriators and leaders worked quickly to revive some semblance of the former regular order for handling spending bills in the Senate. The bills came to the floor in two packages in late 2011, some Senate amendments were added, and House and Senate appropriators went through a conference.

But House conservatives added dozens of amendments, many seeking to pare back federal agencies, to the seven fiscal 2012 bills that passed in their chamber before the August 2011 debt limit accord was reached. Few survived in the final bills, as House leaders and appropriators couldn’t count on support from conservatives for the spending packages on the floor.

This year, appropriators likely will wrap up fiscal 2013 appropriations with a six-month continuing resolution in March, a measure that almost certainly will be free of the sort of controversial amendments that were added to the House-passed bills last year.

Congress might escape its reliance on omnibus bills and CRs by having both chambers agree up front in their budget resolutions on spending levels, said former Rep. David R. Obey, a Wisconsin Democrat who served as House Appropriations chairman.

But the last time Congress did that was in 2009, when Democrats controlled both chambers and cleared a fiscal 2010 budget resolution. Six of the dozen annual spending bills were cleared that year as stand-alone measures, with the rest wrapped in an omnibus.

“If you don’t have a realistic starting point, then everything you do is screwed up,” Obey said.

Anne L. Kim contributed to this report.