Sally Kohn is a CNN political commentator and the author of the forthcoming book " The Opposite of Hate ." The opinions expressed in this commentary are hers.

(CNN) Hate is a problem that affects all of us, a reality we were reminded of when Nikolas Cruz walked into Marjory Stoneman Douglas High School in Parkland, Florida, and killed 17 people. As more information about Cruz emerges, it is becoming clear he had a sordid history of espousing racist, homophobic and anti-Semitic views on social media.

But hate doesn't just affect us when it results in ugly and evenly deadly consequences. Hate, in fact, is perpetuated by us all. Of course, Cruz is responsible for his words and his actions. No one made him type "I hate jews, ni**ers, immigrants," just like no one made him pull the trigger last week. But just as it's impossible to separate Cruz's actions from the broader climate of violence, and in particular gun violence, in America, it's impossible to separate his beliefs from the culture around him.

The National Rifle Association didn't put a gun in Cruz's hands, but it has consistently opposed efforts to stop mentally unstable people from buying weapons, fighting attempts to fix loopholes in the background check system and pouring more than $50 million into supporting candidates who back their pro-gun agenda, according to the Center for Responsive Politics, a nonpartisan research group.

Cruz's culpability isn't erased by acknowledging this context. And by the same token, while Cruz is responsible for his views and how he expressed them online, those views also exist within their own larger context. As of late, white supremacist attitudes appear to be more publicly expressed. Hate crimes in nine major US cities -- from desecrations of Jewish synagogues to attacks on Muslims -- rose an average of more than 20% in 2016, a rise that the Center for the Study of Hate and Extremism attributes to the candidacy and election of President Donald Trump as well as more victims stepping forward, according to Reuters.

From the day he announced his candidacy, Trump has attacked Mexicans, calling them rapists and drug dealers; tried to ban people from Muslim-majority countries from entering the country; and mocked a disabled reporter. And when a woman was killed last year in Charlottesvillle, Virginia, while protesting a white supremacist rally, he was uncharacteristically demure when asked to denounce this hateful ideology.

But this goes beyond Trump. It's impossible to separate attitudes of white supremacy, sexism, xenophobia and homophobia from the broader history and context of our country. The United States, after all, was founded by white people who slaughtered and expelled American Indians and then enslaved Africans to build everything from farms to railroads to the Capitol.

That's a fact, just as it's a fact that up until fairly recently in our nation's history, black people and women didn't have the same rights as white men -- and many still don't have access to equal opportunities.

And while overt expressions of racist or sexist beliefs are troubling and problematic -- as is the stoking of them by political leaders -- the simple fact is we've all grown up in an environment where hateful beliefs are prevalent. Though many of us will pat ourselves on the back for not being overt bigots, let's not fool ourselves. Those hateful views can find a home in the recesses of our minds. And it's this unconscious bias that often unjustly plays out in patterns of policing, hiring, bank lending, school admissions and more.

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It appears Nikolas Cruz was an explicit bigot -- and, thankfully, an exception to the rule in many ways. But his bigotry reflects a kind of hate that is pervasive in our society, and to degrees, in all of us.

When it comes to hate and violence, we need to hold perpetrators accountable while simultaneously examining the climate and context that creates them -- and look at whatever it is that we, as a society, can do to prevent future atrocities.

Just as we need to stop treating each mass shooting as an isolated incident and finally do something about the pro-gun policies and culture that enable such incidents, we need to understand the hate expressed by shooters is also connected to -- and fueled by -- a broader context. And when we realize how these incidents and mindsets are connected, we can begin to address the habits of violence and hate that we, unconsciously or consciously, perpetuate, too.