Now that Mitch McConnell is aboard, how much would earmark ban save?

Senate minority leader Mitch McConnell has agreed to back a ban on earmarks. 'Pork barrel' projects in appropriations bills account for between 1 and 2 percent of total federal spending.

Senate Minority Leader Mitch McConnell has reversed course and now says he’ll back a ban on earmarks. That makes it more likely that such a ban will take effect, as House Republicans and President Obama have already said they’d support ending the practice of allowing lawmakers to direct federal dollars to individual projects in their home districts or states.

Ending earmarks would be a big win for tea party groups, since curbing excess government spending is perhaps their number one priority.

“Parochial, wasteful, pork-barrel earmarks have been wasting money for years here, and it’s kept our focus on local parking garages rather than the nation’s business,” said Sen. Jim DeMint (R) of South Carolina, a tea party supporter, on CBS Tuesday morning. “I think this is the beginning of a cultural change away from the culture of spending.”

But how much money would ending earmarks actually save?

The answer: not so much, in the context of the entire federal budget. Earmark projects in appropriations bills account for between one and two percent of total federal spending, depending on the year and the methodology used in counting.

The Congressional Research Service (CRS), for instance, looked at the issue in-depth a few years ago, and found that in fiscal 2005 1.92 percent of total federal outlays were earmark projects.

Furthermore, some budget experts question whether ending earmarks would reduce spending at all. That is because striking out earmark language does not necessarily reduce the total amount of money appropriated by congress for, say, bridge construction. It just relieves the Department of Transportation of the need to pay for a particular bridge in a particular place.

“Eliminating earmarks absolutely doesn’t reduce spending. All it does is change the place where the spending decision is made from the legislative to the executive branch,” wrote Stan Collender, a former staffer for both House and Senate Budget Committees, in a recent post on his Capital Gains and Games blog.

This is why Sen. McConnell has opposed earmark reforms in the past. He sees it partly as a separation of powers matter, in which giving up earmarks equates to giving up a congressional prerogative.

However, critics of earmarking point out that even two percent of federal spending is a lot of money. In fiscal 2005 that came out to $47.4 billion, according to CRS.

And eliminating earmarks would also end a situation where everyone in Congress has a vested interest in approving larger and larger appropriations bills, say earmark critics. In that sense it might indeed result in a reduction in overall federal spending.

“It greases the skids for more spending.... We need to end this, because you’ve got over 500 congressmen and senators today who think they’re here to take home the bacon,” said Sen. DeMint on CBS.

Presumptive House Speaker-to-be John Boehner has already indicated that House versions of appropriations bills will be earmark-free in the next Congress. President Obama has been less sweeping on the subject, but supportive nonetheless.

“As President, I’ve called for new limitations on earmarks and set new, higher standards of transparency and accountability,” said Obama in a Monday statement after Sen. McConnell decided to support the earmark ban.

But Senate Democrats may not go along. Majority Leader Harry Reid, fresh from a bitter reelection battle, has said it will be up to every individual senator to decide whether earmarks are in his or her state’s best interest.