By John Gramlich, CQ Roll Call

President Barack Obama’s plan to reduce gun violence was initially estimated to cost $500 million. But the package of proposals could cost nearly nine times that much, or $4.5 billion, if Obama gets his wish to pour an additional $4 billion into a Justice Department grant program that helps localities hire police officers.

Republicans — some of whom have been uneasy about the Community Oriented Policing Services (COPS) program for years — are raising questions about the cost of the proposal as well as its timing, which comes as the GOP is trying to force the administration and Senate Democrats to make deep spending cuts.

Obama first proposed the surge in spending on the COPS program as part of a jobs package he called on Congress to pass in September 2011. The jobs package went nowhere, but Obama is reviving its proposal for more police spending as part of a broader agenda on gun violence that he announced at the White House on Jan. 16. Other aspects of his plan, such as an initiative to provide schools with more “resource officers,” psychologists, social workers and other personnel, also would require new congressional appropriations.

Obama and top deputies, including Vice President Joseph R. Biden Jr. and Attorney General Eric H. Holder Jr., have highlighted their commitment to the expansion of the COPS program in recent days, but the president did not mention its cost when addressing gun violence during his weekly radio address Jan. 19.

“At a time when many communities have been forced to make cuts to their police force,” Obama said, “we should put more cops back on the job and back on the street.”

On the day Obama announced his plan, Sen. Charles E. Grassley of Iowa, the top Republican on the Senate Judiciary Committee, issued a warning about the cost.

The president’s gun proposals “face an uphill battle in Congress, especially those that include billions of dollars in new federal spending at a time when the government’s credit card is maxed out,” Grassley said.

Rep. Lamar Smith of Texas, a senior Republican on the House Judiciary Committee, said that he had not yet seen the full price tag of the president’s gun violence plan but that any significant new spending would be cause for alarm.

“My opposition to it has been for other reasons, but [the] spending will give me one more,” Smith said.

The COPS program is currently funded through the fiscal 2013 continuing resolution at $198.5 million, according to the Senate Appropriations Committee. Obama’s proposal would provide “a one-time injection that would be part of our request for the next fiscal year but not the ongoing request,” a White House official said in an email, while declining to answer a question about how the proposal would specifically address gun violence, beyond putting more police officers on the streets.

The program, created in 1994 under President Bill Clinton, has seen its fortunes rise and fall on Capitol Hill in recent years. Congress provided no funding at all under President George W. Bush in 2006 and 2007, but included $1 billion in the 2009 economic stimulus package that Obama signed into law. Under the president’s latest proposal, COPS would receive four times that amount.

Republicans who criticized the stimulus as a giveaway to Democratic-leaning interest groups are raising similar concerns now, with some questioning the purpose and the effectiveness of the COPS program.

Rep. Jim Sensenbrenner, R-Wis., said in a statement to CQ Roll Call that the White House is seeking to inject a significant amount of federal dollars into an area — the hiring of police officers — that should be the domain of state and local governments.