By Anna Douglas

President Barack Obama's blueprint to address gun violence touches every major aspect in the gun control debate: background checks, mental health issues and flaws in the federal system that tracks who can buy a gun.

But his gun control measures aren't as weighty as the proposals he's tried to persuade Congress to pass in recent years.

Much of Obama's executive action playbook relies on simply improving existing regulations and clarifying rules already enforced by federal agencies. And some of his initiatives could fall flat if budget writers in Congress refuse to allocate money for improved mental health services and additional federal agents who police gun ownership.

Here's a look at how background checks are currently done, why Obama is using executive powers and whether local communities can be roused to tackle gun control.

What does federal law say now?

Only federally licensed firearms dealers _ generally retail stores, manufacturers, pawnshops and others who make a living selling guns _ are required to perform background checks on every sale. Private sales, which make up nearly 40 percent of all gun sales, are exempt from background checks under federal law.

Such an exemption has led to use of the phrase "gun show loophole," a term that gun control advocates sometimes use to point out gaps in federal gun law.

But a patchwork of state laws governs the issue too. For example, states such as California and New York require universal background checks for every gun sale, including gun shows and private sales. Other states, like North Carolina, require buyers to undergo background checks to obtain handguns or concealed carry permits.

Obama's proposal seeks to clarify how the federal Bureau of Alcohol, Tobacco, Firearms and Explosives enforces background check requirements. Anyone "engaged in the business" of selling a gun, according to White House officials this week, will need a federal firearms license and will be required to do background checks on buyers.

The ATF, under Obama's announcement, may consider a person to be a gun dealer even if he or she is selling firearms only online or at gun shows. Previously, those individuals may have been considered private sellers exempt from background checks.

How did we get here?

Faced with congressional stalemates over various proposals and powerhouse lobbying by the National Rifle Association, Obama and fellow Democrats have had little success in recent years on gun control.

Despite popular opinion polls showing the majority of Americans favor universal background checks, Congress has not passed such legislation, even in the days and weeks immediately following deadly, high-profile mass shootings. In 2013, shortly after the massacre at an elementary school in Newtown, Conn., a universal background-check bill _ written by a Republican senator and a Democratic senator _ to address Internet gun sales and the so-called gun show loophole failed.

Some critics say universal background checks won't prevent criminals from obtaining guns through illegal means or prevent people who can buy guns legally from using them later to kill. On the other hand, proponents point to statistics from states that have loosened background-check laws and later experienced an uptick in gun homicides, higher than the national increase.

Members of Congress have split over restoring federal funding for government agencies to study gun violence. Democrats have tried unsuccessfully multiple times and ways _ including as recently as last month, during delicate budget-deal negotiations _ to allow the Centers for Disease Control and Prevention to research gun death rates and causes. Republican leaders balk at the idea, contending gun violence isn't a disease.

Congress also has not renewed a previous federal ban on assault weapons, though Democrats have introduced such legislation several times since the ban expired in 2004. The latest bill aimed at stopping assault-weapon manufacturing and making it harder to buy assault weapons already available was introduced last month in the U.S. House of Representatives.

Given the steep challenges Obama faces with a Republican-controlled Congress, he's now addressing the issue through executive actions and looking to rally local officials around his cause.

What can cities and counties do to regulate guns?

Obama's push to gain more traction around the country on gun control will likely meet legal challenges if local officials try to pass city or county gun laws.

Most states have laws prohibiting local jurisdictions from passing any gun control regulations that would be more restrictive than state law, according to the National Rifle Association and the Law Center to Prevent Gun Violence _ two key advocacy groups that generally are on opposite sides of the debate over gun control.

States that give local elected officials little flexibility for policies restricting guns include Florida, Georgia, Idaho, Illinois, Kansas, Kentucky, Mississippi, Missouri, North Carolina, Pennsylvania, South Carolina, Texas and Washington.

In California, cities and counties are allowed to regulate some areas involving guns. But localities are generally prohibited from passing laws that would undermine California's strict gun purchasing and licensing requirements.

What impact does executive action have?

The president's recently proposed gun control and safety measures may have only modest effects _ as did his last major round of gun executive orders, in 2013.

Although some of Obama's 2013 executive measures may have been useful _ including improving data collection _ they were "pretty small-bore items that show the limitation of what a president can do with executive action on any given subject," said Robert Spitzer, a political scientist at State University of New York-Cortland who has written extensively on gun control.

A president's power, Spitzer said, is limited, compared with what Congress could achieve through legislative action.

Although requiring more gun sellers to obtain federal licenses will increase the number of buyers who undergo background checks, the "actual consequence is likely going to be fairly small," Spitzer said.

And some of Obama's measures may still require congressional approval, including his request for money to hire 200 new agents and investigators for the Bureau of Alcohol, Tobacco, Firearms and Explosives, and $500 million to increase access to mental health services.

Already, the president is hitting stumbling blocks related to his 2013 orders. Then, he urged Congress to confirm a permanent leader for the ATF, saying lawmakers needed "to help, rather than hinder, law enforcement as it does its job."

The Senate confirmed acting director B. Todd Jones several months later, but Jones left the agency last March and it is again without a permanent director.

(Lesley Clark contributed to this report.)

(c)2016 McClatchy Washington Bureau