Kamala Harris is a US Senator for California and a Democratic presidential candidate. The views expressed here are hers. Read more opinion on CNN.

(CNN) As a career prosecutor and former attorney general of California, I saw firsthand how counterproductive marijuana laws exacerbated the problem of mass incarceration in my state and in our country -- leading to the disproportionate criminalization of black and brown people in particular.

The fact is, marijuana laws have not been enforced in the same way for all people. Data show that a person of color is much more likely than a white person to be arrested for marijuana possession, despite evidence that Americans use marijuana at nearly the same rate, regardless of race.

As public opinion of marijuana shifts toward legalization , it's time we do the smart thing -- the right thing -- and ensure any marijuana reform legislation we put on the table adequately addresses the harm caused by the failed drug policies of the past.

To protect states like California that have legalized or decriminalized marijuana in recent years, we must act at the federal level to ensure that the US Department of Justice does not encroach to enforce laws that voters and elected officials in those states have decided are unjust and unfair. Additionally, we have to make sure that widespread reform is felt by the communities most harmed by the so-called war on drugs.

Last week, the House of Representatives passed the Secure and Fair Enforcement (SAFE) Banking Act. While its passage is a promising step forward in allowing legal marijuana businesses to access basic banking services -- it is not enough. That is why I am proposing we do more than simply remove barriers to financial services. We should get smart on marijuana reform.

JUST WATCHED Why cannabis stocks are soaring Replay More Videos ... MUST WATCH Why cannabis stocks are soaring 03:10

First, the bill acknowledges that legalization is only one part of the solution. In addition to legalizing marijuana at the federal level by removing it from the Controlled Substances Act , our bill goes further to add measures to correct the historical injustices of failed drug policies that have disproportionately impacted communities of color and low-income communities.

Second, in keeping with our belief that times have changed and marijuana should not rise to a criminal offense, we must make sure individuals with criminal records that stem from marijuana-related offenses are able to get on with their lives. Too often, people are barred from jobs, educational opportunities and housing due to their marijuana record. That is why this bill requires federal courts to conduct resentencing hearings and expunge nonviolent marijuana-related convictions. It would also protect Americans from being denied federal benefits based on their use or possession of marijuana or prior conviction for a marijuana offense.

Third, my proposal would deliver economic justice to affected communities. The marijuana business is one of the fastest growing money-making industries in today's economy, and individuals and communities disproportionately criminalized by the enforcement of marijuana laws should be first in line to benefit from today's legal marijuana industry. Our bill would authorize a 5% sales tax on marijuana and marijuana products to create new grant programs specifically designed to support businesses owned by socially and economically disadvantaged individuals entering the legal marijuana industry. It would also provide funding for programs to help minimize barriers to marijuana licensing and employment.

Get our weekly newsletter Sign up for CNN Opinion's new newsletter. Join us on Twitter and Facebook

We must ensure that as marijuana becomes a bigger business, we are committing ourselves to rebuilding communities that have been disproportionately targeted by failed drug policies and creating a diverse industry going forward. If we fail to address a system that has historically been infected by racial bias, communities of color will continue to shoulder the devastating impacts of the past.

Times have changed. We must get smart on marijuana reform and give everyone the opportunity to reap the benefits that come from the legal marijuana industry.