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President Obama is trying to enlist the public's help to urge lawmakers to act on his proposals to curb gun violence, telling Americans, "It's got to be up to you" to make a difference.

On Wednesday, Obama unveiled his plan to halt gun violence in America through a comprehensive package of legislation and executive actions. The president is calling for a ban on some types of semiautomatic assault rifles, mandatory background checks for all gun purchases, a ban on high-capacity magazines holding more than 10 rounds, and cracking down on illicit weapons trafficking.

"None of this will be easy," the president says in his weekly address. "Already, we're seeing pundits, politicians, and special-interest lobbyists calling any attempt at commonsense reform an all-out assault on liberty - not because that's true, but because that's how they get higher ratings and make more money. And behind the scenes, they're doing everything they can to protect the status quo."

"But this time, it can't be up to them. It's got to be up to you," he says.

The White House is launching a public campaign to turn up the heat on Congress, and Obama's grassroots supporters are mobilizing to push the president's agenda.

"Ask your member of Congress if they support universal background checks and renewing a ban on military-style assault weapons and high-capacity magazines. And if the answer is no, ask them why not. Ask them why an 'A' grade from the gun lobby is more important than keeping kids safe in a first grade classroom," the president says.

Obama reads from a letter he received in the wake of the deadly school shooting in Newtown, Conn., from an 8-year old girl named Rachel. "She wrote: 'Please do something so that bad people cannot get guns to kill other people. Children should be safe, especially in school.'"

"Rachel is counting on us. Let's get this done for her, and let's make this country a safer place for all our children to learn and grow," he concludes.