The following column is the opinion and analysis of the writer.

When I came back to Washington in January and was sworn in to serve in the new Congress, the House passed HR 8: the Bipartisan Background Checks Act of 2019 — a promising way forward. Since then, an estimated 6,819 people have been killed by gun violence.

And yet, Senate Majority Leader Mitch McConnell refuses to bring this bill to the Senate floor. Why? Because apparently money from the National Rifle Association (NRA) speaks louder than the outcry from American families over lives lost to gun violence.

I wasn’t always an outspoken advocate for gun reform. I was a gun owner and grew up hunting with my father — that was a part of living in rural Arizona. In fact, when I was first elected to Congress in 2008, the NRA gave me an “A” rating. That’s changed as countless unconscionable acts of gun violence have ravaged our country.

My evolution began on January 8, 2011, when my good friend and mentor, Gabby Giffords, was shot in the head with a handgun. During that “Congress on Your Corner” event, Congresswoman Giffords and 18 of her constituents fell victim to gun violence.

Six innocent people were murdered that day. The youngest killed was a 9-year-old girl.

These violent shootings occur so frequently that we’ve become numb to them.

Children as young as 5 are dying in their classrooms, and Americans of all ages are being murdered at concerts, clubs and places of worship.

I was taking a break from the campaign trail last year and babysitting my grandchildren when the news out of Parkland, Florida, unfolded, shocking me to my core. How could we allow more killing for no reason other than our failure to regulate violent weapons? How could I explain to my grandchildren why they have lockdown drills at school?

We had been asking these questions since Sandy Hook. But Parkland felt different. Not only was there a new debate, there were new players, too. Teenagers began challenging the NRA on cable news. Students and teachers protested in their schools. Over 200,000 people marched to the U.S. Capitol in the “March for Our Lives,” and more than 800 cities around the world marched in solidarity, including Tucson.

There was a change on the campaign trail. Candidates in 2018 didn’t court the NRA — they ran with endorsements from Moms Demand Action, Everytown for Gun Safety, the Giffords Courage PAC, and others. My campaign prioritized background checks for gun purchases, because voters demanded answers. This energy traveled to the ballot box; a record number of women were elected to the 116th Congress to advocate for the safety of our families.

Unlike my freshman colleagues, it wasn’t my first time in Washington. I was returning to Congress after a few years away, with ideas inspired by changing attitudes on the ground. However, I soon realized that Washington had not evolved like I had — voices are still being silenced by the NRA.

An overwhelming 87% of Americans want universal background checks on gun sales. This number should compel action. The leaders Americans elected in 2018 understand that: In our first month in office, we passed the Bipartisan Background Checks Act of 2019, the first gun-safety legislation to pass the House in over 25 years.

But the Republican-controlled Senate, led by McConnell, remains exactly where it was when I left Congress: buried inside the pocket of the NRA. Rather than prevent future tragedies, Republican officials are working to rake in more campaign donations from the gun lobby. Leader McConnell himself has received over $1.26 million from the NRA. Additionally, between January 2010 and December 2016, the NRA injected $58 million into congressional and state legislature elections across the country.

The NRA is a 501c(4) nonprofit, meaning that much of its spending is not subject to limits nor transparency. This “dark money” makes its way into the advocacy for election or defeat of federal candidates; in 2012, the NRA spent more than $7 million on this effort. In total, between 2010 and 2016, the NRA spent $110 million on dark-money contributions.

The NRA’s money and influence has drowned out the message Americans sent in the 2018 midterm elections. Worst of all, it has allowed gun violence to become an American epidemic.

We cannot continue to accept politicians who have fistfuls of NRA cash and mouthfuls of “thoughts and prayers.”

It’s time to hold our elected officials accountable. If we don’t, we risk losing even more lives to senseless gun violence.

To my colleagues in the Senate: I challenge you to show courage by passing HR. 8. To all American voters: If your representatives aren’t acting on your demands, I challenge you to speak out. Or better yet, vote them out.

Ann Kirkpatrick is a Democrat serving as the U.S. representative for Arizona’s Second Congressional District. She previously represented Arizona’s First Congressional District from 2009 to 2011 and again from 2013 to 2017.