Nearly the entire House Democratic caucus has signed onto a letter demanding that Speaker John Boehner (R-Ohio) move to pass gun control legislation.

Supporters of a new gun rights bill hold signs prior to a hearing on gun rights laws at the Statehouse in Boston, Tuesday, June 3, 2014. (AP Photo/Charles Krupa)

Gun control legislation has proven virtually impossible to get through Congress, and the issue is rarely an election-year winner. But pushing gun control could mobilize the Democratic voter base in a tough 2014 midterm season, as base voter turnout is generally the key to survival in off presidential election years.

“Gun violence has affected constituents in every congressional district, and as their representatives, members of Congress deserve the opportunity to vote on bills that would address this epidemic,” the letter said.

President Barack Obama during a town hall on Thursday called on gun control advocates to become as well-organized and well-financed as the National Rifle Association.

The House Democrats’ letter, signed by 163 members, said Congress “must honor the victims of the recent shootings in Portland, Las Vegas, Seattle and Santa Barbara.”

Rep. Mike Thompson (D-Calif.), the chairman of the House’s Gun Violence Prevention Task Force, and task force member Rep. Carol Shea-Porter (D-N.H.). circulated the letter. In 2013, the task force released a gun control agenda with several proposals.

In 2013, an Obama-backed bill to strengthen background checks lacked enough support to get through the Democratic-controlled Senate.

The Democrats assert that this is a result of various loopholes in background checks that allows straw purchasers.

“Dozens of legislative proposals that address these factors have been introduced and await consideration,” the letter said. “But despite wake-up call after wake-up call, a shameful tradition of congressional inaction continues.”

Congressional silence is not a sign of respect, but rather an institutional indictment,” it continued. “We must right this wrong.”

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