WASHINGTON - Despite their claims, the Republicans' ban on earmarks won't stop lawmakers from steering taxpayer dollars to pet projects. And it will have little if any effect on Washington's far graver problem - the gigantic budget deficit.

Saying that Election Day victories gave them a mandate to curb spending, Republicans formally agreed last week to a two-year prohibition of earmarks, legislative provisions that funnel money to lawmakers' favorite projects. President Obama has said he, too, wants to restrict earmarks, though he defended some as helping communities.

"I am proud that House and Senate Republicans have united to end the earmark favor factory," said Sen. Jim DeMint (R., S.C.), a leader in the drive to stop the practice.

While the ban will make it harder for lawmakers to bring pork-barrel spending back home, it is far from airtight.

Savvy members of Congress have options such as "phone-marking" - picking up the telephone and pressuring agency officials to spend money on specific projects. Lawmakers are sure to exploit uncertainty over exactly how the ban will be applied, such as whether it will bar money for projects already in the works. And Democrats, who will still run the Senate next year, have not agreed to the restrictions. Neither have some Republicans.

"There's no way you can stamp out every effort" by lawmakers to bring home the bacon, said Rep. Jeff Flake (R., Ariz.), another leading earmark foe. "But you can marginalize it."

Even completely eliminating earmarks would hardly ensure that spending decisions will be objective and divorced from politics. Presidents and agency officials control where many federal dollars go and have always used that power to reward allies. And formulas that automatically disburse other funds to states are themselves products of past political compromises.

"It makes those who ranted and raved against earmarks feel good," Robert Reischauer, the Urban Institute president and former chief of the nonpartisan Congressional Budget Office, said of the GOP ban. "But it is largely cosmetic."

Spending for earmarks peaked in 2006, when lawmakers diverted $29 billion to hometown projects, according to Citizens Against Government Waste. That dipped to about $16 billion last year for 9,000 earmarks, thanks to public pressure and the infamy of influence-seekers like convicted lobbyist Jack Abramoff.

That $16 billion amounts to just half of 1 percent of the $3.5 trillion federal budget. Lawmakers carve most earmarks from within agency budgets, so eliminating them would not save money but simply mean it would be spent on something else.

Even if the ban somehow did save $16 billion, it would fail to make a noticeable dent in the deficit, which hit a near-record $1.3 trillion last year and threatens to remain huge.

Former Rep. Bob Livingston (R., La.), who doled out many earmarks as chairman of one of Congress' spending committees, said he believed the ban would reduce earmarks but have no real budgetary impact.

"It's a symbol, and my friends and former colleagues have chosen to bow to a symbol," said Livingston, who is now a lobbyist.

Critics of earmarks say they generally go to senior lawmakers, divert funds from worthier projects, and are doled out by leaders in exchange for votes on other bills that drive up spending even further. They are a favorite target of conservatives.

Yet earmarks remain popular with many lawmakers who consider it part of their jobs to win money for deserving projects back home - and view the projects as a way to please voters.

Sen. Lisa Murkowski (R., Alaska), just reelected over a tea party rival in a campaign in which she championed earmarks, opposes the ban and said she "will always fight hard to ensure that Alaska receives its fair share."

Sen. Lamar Alexander of Tennessee, a member of the GOP leadership, said he would back the moratorium but would seek money for his state for emergencies like floods - perhaps opening the door for other lawmakers who might seek earmarks by claiming their states were facing their own problems.