U.S. Democrats must avoid appearing too heavy-handed in what will likely be a push for more gun control when Congress reconvenes in January after Friday' s grizzly school shooting spree, experts said.

Calls are growing louder for Congress to take action after a gunman shocked the nation last week when he killed 20 children aged six and seven, as well as six adults, at an elementary school in the state of Connecticut.

Authorities said the shooter, 20-year-old Adam Lanza, shot his mother four times in the head before driving to Sandy Hook Elementary School in Newtown, Connecticut, spraying two classrooms with bullets and killing himself.

On Monday, White House Spokesman Jay Carney reiterated President Barack Obama' s statements that in the coming weeks he would engage "lawmakers, law enforcement, mental health experts, educators and others in an effort to try to prevent these kinds of terrible tragedies from happening in the future," but added that Obama has not yet espoused an official agenda.

But for any serious discussion on gun control to be successful, anything seen as a naked power grab on guns is likely to fail, said Republican strategist Ford O'Connell.

Indeed, gun owners have long been skeptical of the government exercising what they view as too much control over their constitutional right to bear arms, and any bill seen as too heavy handed is unlikely to pass in the GOP-controlled House of Representatives in a bitterly partisan Congress.

Moreover, those advocating greater gun control will have to tackle every issue associated with what happened on Friday in Newtown, Connecticut, from mental health issues to questions on what some see as a U.S. culture of violence, O'Connell said.

Two Democratic Senators, California' s Dianne Feinstein and New York' s Chuck Schumer, are leading to charge for gun legislation, with Feinstein appearing Sunday on NBC' s "Meet the Press" to announce she will introduce legislation limiting the sale and ownership of automatic weapons as her first order of business in the coming Congress.

But the two lawmakers rank high on a recent National Journal list of the most liberal senators, based on last year' s voting records. O'Connell said for any gun legislation to pass it would have to involve more moderate voices, such as West Virginia Democrat Sen. Joe Manchin.

Manchin, a lifelong National Rifle Association member and one of Congress' most conservative Democrats, called Monday for talks on reasonable gun restrictions and urged people not to be afraid to have the discussion.

Prior to Friday' s massacre, Democrats have been hesitant to discuss gun control out of fear of losing the support of their rural constituents.

The anti-gun debate was a hot-button issue in the 1990' s, but the issue faded from public discourse after the expiration of a 10-year ban on assault weapons in 2004. While there have been more than a dozen mass shootings this year, most elicited a muted response from anti-gun lobbyists and the news media.

But because small children were the main victims of last week' s killings, experts expect the debate to come roaring back to life.

"The large number of people killed plus the deaths of 20 very young children puts a human face on this subject that we really haven't had before," said Darrell M. West, vice president and director of governance studies at the Brookings Institution.

However, gun owners' rights groups, such as the National Rifle Association, are expected to put up a fight against any measures they deem unfair.

Gun owners have long made the argument that too much gun legislation leaves more firearms in the hands of criminals -- criminals tend to obtain firearms illegally -- and deprives law-abiding citizens of the ability to defend themselves against robberies, home invasions, rape, murder and a host of other crimes.

Some gun rights advocates also argue that mass killings tend to occur in places where guns are banned, such as movie theaters and shopping malls, giving mass shooters free rein to kill at will without the fear of getting shot themselves.

They also note that despite strict regulations in places like Washington DC, the city is a hotbed of gun violence, because criminals are not thwarted by regulations and often purchase guns illegally.