In urging law enforcement leaders to back new gun control efforts, President Barack Obama is asking police chiefs and county sheriffs to unite behind a cause they don't even agree about among themselves.

Obama said Monday that he was seeking a "basic consensus" among law enforcement executives to pressure Congress for legislation to ban assault-style weapons and restrict high-capacity ammunition magazines, among a score of other measures.

But it turns out the two national groups representing police and sheriffs at a meeting of law enforcement officials Monday at the White House — the Major Cities Chiefs Association and the Major County Sheriffs Association — disagree on the initiative. The chiefs back it, while the sheriffs oppose it.

Philadelphia Police Commissioner Charles Ramsey, president of the police chiefs group, said the deaths of 20 students and six teachers and staff members at Sandy Hook Elementary School in Newtown, Conn., last month had settled the issue.

"If the slaughter of 20 babies does not capture and hold your attention, then I give up, because I don't know what else will," Ramsey said last week. "We have to pass legislation."

But in a letter to Vice President Joe Biden (.pdf), who is leading the White House lobbying effort, the sheriffs group argued that "a ban on assault weapons alone will not address the issues of gun violence we are facing in our country today."

Nor would limiting magazine capacity, it said: "The problem is not the law-abiding citizen that will follow the restrictions; the problem again is one of access. ... (E)ven if you can’t buy in bulk, you can still buy multiple boxes of smaller quantities."

Similarly, the International Association of Chiefs of Police said in a position paper (.pdf) that it was "a strong supporter of the assault weapons ban" and measures to limit ammunition capacity. But the Constitutional Sheriffs and Peace Officers Association applauded what it called efforts to "uphold and defend the Constitution against Obama's unlawful gun control measures."

Chiefs vs. sheriffs
The divide reflects a cultural and political gulf between police chiefs and sheriffs in a number of areas, criminal justice experts told NBC News.

Police chiefs run departments in cities where most gun crimes take place, according to FBI crime statistics over the past decade. Sheriffs run departments in counties, some or all of their jurisdictions covering rural areas where hunting and sport shooting are cherished rights. As a result, "you have these wildly different views of guns," said Gary Kleck, a professor of criminology and criminal justice at Florida State University in Tallahassee.

In counties, particularly heavily rural ones, "guns equal hunting, fishing, father-and-son-bonding-type things," he said, while in cities, "guns equal crime."

Those community views have real political effects, according to Kleck and another expert, Scott H. Decker, a professor of criminology at Arizona State University in Tempe.

"The big difference is a sheriff is elected and has to face the voters every four years," Decker said, but police chiefs are almost always appointed.

"If you're a police chief, you're not responsible to an electorate," Kleck said, and are therefore more free to advocate for politically unpopular policies like bans on certain kinds of weapons.

Sheriffs vs. sheriffs
Decker suggested that there was likely to be a broad range of opinion among sheriffs, because it's not just elections that keep them in touch with community sentiment. Because they have more varied duties — running jails and patrolling areas that can include rural, suburban and urban communities, all in the same county — their jurisdictions range across populations with widely different political views on guns.

So while many sheriffs say they wouldn't enforce new federal gun control laws, there are other sheriffs who call those sheriffs misguided.

Last week, Milwaukee County (Wis.) Sheriff David Clarke issued a public service announcement urging residents to learn how to handle a firearm "so you can defend yourself until we get there."

"With officers laid off and furloughed, simply calling 911 and waiting is no longer your best option," Clarke says in the spot, which you can listen to here.

Just a few counties over, Ron Cramer, sheriff of Eau Claire County, objected that Clarke was sending the wrong message.

Clarke could have gotten across his point that residents could take more responsibility for their own safety "without having to say it's time to join our team and pick up a gun," Cramer told NBC station WEAU of Eau Claire.

Related links:

• Newtown residents join gun control march in Washington
• Colorado sheriff blasts colleagues over refusal to enforce gun laws
• Sen. Feinstein introduces stringent assault weapons ban

Florida Gov. Rick Scott has shot down a request by Tampa's mayor to allow local authorities to ban guns from the city's downtown during the Republican National Convention in August.

Citing Second Amendment protections in the U.S. Constitution, Scott told Tampa Mayor Bob Buckhorn that conventions and guns have co-existed since the nation's birth and would continue to do so during the four-day event beginning Aug. 27.

"It is unclear how disarming law abiding citizens would better protect them from the dangers and threats posed by those who would flout the law," the Republican governor said in a letter on Tuesday.

Local officials need Scott's permission to enact the temporary restrictions after state lawmakers last year passed a measure that prohibits local governments from adopting gun ordinances that are stricter than state law.

Florida has some of the most lenient gun laws in the United States and by some counts leads the nation in gun ownership, with about 6.5 percent of all adults licensed to carry a concealed weapon, state records show.

New applications for concealed gun permits have quadrupled since 1998.

In a letter to Scott, Buckhorn said the Tampa City Council had banned a host of items from the area surrounding the convention facility, a list that includes water guns, poles and pieces of wood.

"One noticeable item missing from the city's temporary ordinance is firearms," Buckhorn wrote. "In the potentially contentious environment surrounding the RNC, a firearm unnecessarily increases the threat of imminent harm and injury to the residents and visitors to the city."

Scott said he was confident law enforcement officials, who are expected to number nearly 4,000, would be able to protect the public without having to enforce a blanket gun ban.

That city officials have banned other items is irrelevant, he said.

Watch the most-viewed videos on msnbc.com

"The choice to allow the government to ban sticks, poles but not firearms, is one that the people made in enacting their state and federal constitutions," Scott wrote. 

Weapons will not be allowed in the convention center itself or in the immediate area surrounding the site. Security in that venue is being handled by the U.S. Secret Service. 

The City Council wants to extend the restrictions to all of downtown, including areas that have been designated zones for protesters expected at the event. 

"As governor, you have the duty to meet dangers presented by events such as the RNC where there is a threat of substantial injury and harm to Florida residents and visitors to the state," Buckhorn wrote.

More content from msnbc.com and NBC News:

• Judge: Prosecutor's rejection of gay juror 'shocking'
• George Zimmerman's old Myspace page includes slurs against Mexicans
• Chicago pays $45 million in 3 years to settle complaints against cops
• Maryland court finds pit bulls are 'inherently dangerous'
• NJ mom arrested after allegedly taking daughter, 5, tanning

Follow US News on msnbc.com on Twitter and Facebook