Gun-Control Protester
People hold signs memorializing Sandy Hook Elementary School, where 26 children and adults were killed in a mass shooting in 2012, as they participate in the March on Washington for Gun Control on the National Mall in Washington, Jan. 26, 2013. Reuters

A political shift seems to be taking place in Colorado, a state rocked by two of the deadliest mass shootings in recent history: The Democratic-controlled House on Monday passed a number of strict gun control bills, despite Republican resistance.

The four measures passed along party lines. If they become law, background checks will be required for every gun transaction; there will be a fee for gun buyers that will cover the cost of those checks; gun magazines will be limited to 15 rounds, and there will be a ban on concealed weapons on college campuses.

The bills will next head to the Senate, where Democrats hold a 20 to 15 advantage. Just 18 votes are needed to clear the way.

Since the killing of 20 children and six adults at Sandy Hook Elementary on Dec. 14, there has been a national debate about passing legislation to tackle gun violence.

President Barack Obama has proposed several measures that include background checks and an assault weapons ban he hopes Congress will act on.

Rep. Rhoda Fields, a Democrat from Aurora, the Denver suburb where 12 people were murdered in a theater and 58 others injured by a gunman last year, also lost a son through gun violence. She sponsored the magazine and background check bills. Aurora is also not far from Columbine High School, where in 1999, two teenagers went on a shooting rampage, killing 13 people and themselves.

“We can no longer walk around in our society with these blinders on as if nothing is happening,” she said in a statement.

“Responsible folks who own guns, they support what I’m doing,” Fields added. “I have support from law enforcement. But most importantly I have the support of the families that have been impacted by gun violence.”

Colorado House Republican leader Mark Waller has called the bills a “knee-jerk reaction” to the mass shootings in Aurora and Connecticut.