Minority Leader Harry Reid, D-Nev., and Sen. Chuck Schumer, D-N.Y., on Oct. 27, 2015. Reuters

UPDATE: 5:29 p.m. EST -- The U.S. Senate voted against an amendment on Thursday that would intensify background checks on gun sales. The amendment, which was introduced by Sen. Joe Manchin, D-W.Va., originally had bipartisan support and was co-sponsored by Sen. Pat Toomey, R-Pa.

A shooting on Wednesday in San Bernardino, California, killed 14 people and was the deadliest mass shooting since the one at Sandy Hook Elementary School in Newtown, Connecticut in December 2012.

UPDATE: 4:45 p.m. EST -- The Senate voted against an amendment introduced by Democratic California Sen. Dianne Feinstein that would prohibit the sale of guns to people who are on the federal government’s no-fly list, which aims at stopping potential terrorists from boarding aircraft.

Democrats hope to benefit politically from Republicans who vote against these measures. Democratic senators accused Republican lawmakers on Thursday of bowing to the influence of the pro-gun lobby, the National Rifle Association (NRA), which is one of the most powerful lobbies in Washington, D.C. The issue of guns being sold to potential terrorists was highlighted by President Barack Obama Wednesday after the shooting in San Bernardino, California.

“For those concerned about terrorism, some might be aware of the fact that we have a no-fly list where people can't get on planes, but those same people who we don't allow to fly can go into a store right now in the U.S. and there is nothing we can do to stop them,” Obama said during an interview with CBS News. “That is a law that needs to be changed.”

UPDATE: 4 p.m. EST -- As Senate Democrats prepare to force a vote on gun control amendments in the wake of the San Bernardino shooting, senators who held a news conference on Thursday afternoon in Washington have tweeted to raise awareness about the issue. Those senators include Democratic presidential candidate Bernie Sanders, I-Vt., Sen. Barbara Boxer, D-Calif., and Sen. Chuck Schumer, D-N.Y.

Original Story:

Senate Democrats took a hard line on military-style weapons on Thursday and repeatedly said that their Republican colleagues lacked the courage to challenge the NRA on issues of gun violence. The senators said the San Bernardino mass shootings were the last straw and that they would force votes on amendments to strengthen gun control in the United States.

“Enough is enough and Senate Democrats are not waiting one more day,” Sen. Charles Schumer, D-N.Y., who is slated to become a Democratic leader in the Senate in the next Congress. “Today’s the day we act.”

Schumer said that Senate Democrats will introduce two amendments to funding bills that they say would help to reduce gun violence. The forced votes, should Democrats achieve their goal, would likely only be symbolic, since Democrats are in the minority in both chambers of the federal legislature. Senators admitted as much Thursday, saying that the amendments were primarily to show the American people where every senator stands on gun control legislation.

NRA | Graphiq

The amendments, according to Politico, would make it harder for those on terrorist watch lists to buy guns and would require a new vote on universal background checks that failed in Congress in 2013. Sen. Minority Leader Harry Reid, in response to the shooting at a Colorado Planned Parenthood last week, has proposed an amendment that would make it more difficult for individuals convicted of attempting to intimidate patients at reproductive health clinics to get a gun.

The amendments would be attached to a bill that President Barack Obama has promised to veto, however the Democrats said that the amendments would rescind much of the underlying language in the bill and transform it into something they say the president would be willing to sign. The president repeated calls for tougher gun control measures after Wednesday's mass shooting.