WASHINGTON – Newly invigorated Senate Republicans are expected to take a small but symbolic step today to show that they’re serious about curbing spending, when they formally back a moratorium on “earmarks,” the thousands of local projects stuffed into legislation that add up to billions of federal dollars.

With a fresh boost Monday from GOP leader Mitch McConnell of Kentucky, Senate Republicans are expected to endorse barring the practice. Republicans in the House of Representatives also plan to vote on a ban later this week.

Earmarks, usually inserted into legislation by lawmakers for bridges, buildings and other pet projects back home, accounted for $15.9 billion of the federal budget in fiscal 2010, which ended on Sept. 30. That was less than 1 percent of all federal spending and would have barely put a nick in last year’s $1.29 trillion deficit.

Still, earmarks have become symbolic to many of Congress’ fiscal indiscipline, and the GOP push to ban them holds political significance.

“I welcome Senator McConnell’s decision to join me and members of both parties who support cracking down on wasteful earmark spending, which we can’t afford during these tough economic times,” President Obama said Monday. “But we can’t stop with earmarks, as they represent only part of the problem. … I look forward to working with Democrats and Republicans to not only end earmark spending, but to find other ways to bring down our deficits for our children.”

Robert Bixby, executive director of the Concord Coalition, a nonpartisan budget watchdog group, said, “It’s a good-government issue more than a fiscal one.”

McConnell echoed that view.

“I don’t apologize for them,” he said in a Senate floor speech. “But there is simply no doubt that the abuse of this practice has caused Americans to view it as a symbol of the waste and the out-of-control spending that every Republican in Washington is determined to fight.”

“Unless people like me show the American people that we’re willing to follow through on small or even symbolic things,” McConnell said, “we risk losing them on our broader efforts to cut spending and rein in government.”

Senate Democratic Leader Harry Reid of Nevada disagreed.

“Senator Reid makes no apologies for delivering for the people of Nevada. He will always fight to ensure the state’s needs are met,” said his spokeswoman, Regan Lachapelle.

The anti-earmark push has been led by Sen. Jim DeMint, R-S.C.

“I am proud that House and Senate Republicans have united to end the earmark favor factory,” DeMint said. “Earmarks have greased the skids for runaway spending and bad policy for decades. It’s time for Congress to stop focusing on parochial pet projects, and instead focus on cutting spending, devolving power and decisions back to states, and working on national priorities like entitlement and tax reform.”