U.S. Sen. Rand Paul (R-Ky.) speaks to students during a discussion on criminal justice reform at Bowie State University in Bowie, Md., on March 13. (Jose Luis Magana/AP)

Rand Paul has made criminal justice reform an important bullet on his political to-do list. He was one of the few white political leaders to speak out forcefully during last summer’s contentious debates around the subject after several unarmed black men and boys were killed during encounters with police officers. He has co-sponsored legislation in Congress to reform mandatory sentencing laws and to change policies that permanently stigmatize nonviolent juvenile offenders, which have disproportionately affected African Americans.

During his announcement speech on Tuesday, Paul again raised the issue of fairness in the criminal justice system. Video elements and speaker intros ahead of his address zeroed in on his efforts to reach out to voters in urban areas and communities of color.

That focus has brought Paul attention -- even some bipartisan praise. It's also an issue that, despite having caught on in some conservative circles, is unlikely to bring him much traction in the Republican primary.

The question facing the newly-minted candidate is how he now reconciles those two realities.

Polls consistently show a gaping gulf between black and white voters over whether there is racial bias in the criminal justice system. Whites believe that blacks and whites are treated the same; black respondents overwhelmingly disagree. White Republicans see even less of a problem than white Democrats.

After years of leading the push for tough policing tactics and harsh sentencing, some conservative politicians and activists have joined the criminal justice reform movement. Alarmed at the costs of one of the world's largest prison systems, they are calling for loosening sentencing guidelines for nonviolent offenders and changing policies that make it more difficult for people to re-enter society after they've served their time. The Koch Brothers recently partnered with several liberal groups, including the Center for American Progress, to create a criminal justice reform initiative called the Coalition for Public Safety.

Many of the GOP presidential hopefuls have talked about the need to reduce the prison population, but few have spoken out as consistently on the issue as Paul, who attributes some of his activism on the issue to his libertarian leanings.

[How Rand Paul's criminal justice pitch is playing on the trail]

A week after a white police officer in Ferguson, Mo., shot and killed Michael Brown, an unarmed 18-year-old, Paul wrote an op-ed for Time Magazine criticizing police for donning camouflage gear and deploying armored vehicles to confront protesters who took to the streets. He also raised the issue of fairness in the criminal justice system.

Anyone who thinks that race does not still, even if inadvertently, skew the application of criminal justice in this country is just not paying close enough attention. Our prisons are full of black and brown men and women who are serving inappropriately long and harsh sentences for non-violent mistakes in their youth.

Paul later showed up in Ferguson, where he met with church and business leaders and activists. The day after a grand jury declined to indict the officer who killed Brown, and a week before a jury in Staten Island decided not to indict a New York City police officer in the choke hold death of Eric Garner, Paul wrote another op-ed for Time  in which he blamed the political system for failing to address the poverty that he argued fuels inner-city violence.

In the search for culpability for the tragedy in Ferguson, I mostly blame politicians. Michael Brown’s death and the suffocation of Eric Garner in New York for selling untaxed cigarettes indicate something is wrong with criminal justice in America. The War on Drugs has created a culture of violence and put police in a nearly impossible situation.

Last year, along with Sen. Cory Booker (D-N.J.), he introduced criminal justice reform legislation that would encourage states to set 18 as the age at which a person can be tried as an adult, and to allow some non-violent juvenile offenders to have their records sealed.

And as recently as last month, Paul spoke at historically black Bowie State University, where he talked about how sentencing laws and overzealous policing disproportionately affects poor people, who are often black.

"Criminal justice, or the lack of criminal justice, it's not a black or white problem," Paul said at Bowie State. "It's a poverty problem."

But a December Washington Post-ABC News poll highlighted just how strikingly divided views about the criminal justice system are based on race. Fifty-two percent of whites said that African Americans receive equal treatment with whites in the criminal justice system. Only 1 in 10 African Americans agreed. The partisan divide among white respondents was notable: 2 in 3 white Republicans said minorities were treated the same as whites in the criminal justice system, versus 3 in 10 white Democrats.

[On racial issues, America is divided both black and white and red and blue]

That raises the question of whether the issue would resonate with an overwhelmingly white GOP primary electorate. In 2012, white voters made up about 94 percent of participants across GOP primaries and caucuses where exit polls were available.

Jasmine Farrier, an associate professor in the political science department at the University of Louisville, says Paul is probably “looking more toward remaking the Republican Party and gaining general election votes.”

“I think he’s trying to develop a national public persona to set himself apart from the rest of the pack,” Farrier said. “If he’s the only person who can say he’s looking at these voters on these issues, it can help elevate his establishment credentials for a general election win because Mitt Romney did not win these communities.”

“These are more than policies, these are signals,” Farrier added.

Paul's campaign did not respond to a request for comment on the question of whether he will make criminal justice reform a major part of his appeal to primary voters. Although black voters are generally few in the GOP primaries, it didn't deter his father, Ron Paul, from campaigning in inner city Detroit in 2012.

Ron Paul got a standing ovation, according to Mlive.com, when he told a crowd at a black church: "One of the most serious places where racism still exists is in our judiciary. It is so often related to both immigration policies, where people are targeted because they look a certain way, and the drug war ... if you happen to be a poor minority, disproportionately, you're more likely to be arrested."

Rand Paul has only been an official candidate for a few hours, but the campaign Web site he unveiled Tuesday included a criminal justice explainer that laid out, in detail, his position on the issue. "Although I was born into the America that experiences and believes in opportunity, my trips to Ferguson, Detroit, Atlanta, and Chicago have revealed that there is an undercurrent of unease brought forth by our unjust criminal justice system," he wrote.

In remarks delivered at his official launch event, the list of places he'd visited had shifted a bit. "Although I was born into the America that experiences and believes in opportunity, my trips to Detroit, to Appalachia, to Chicago have revealed what I call an undercurrent of unease," he said -- though he no longer tied that unease to the criminal justice system, instead nodding briefly at the end of his speech to "an America where criminal justice is applied equally and any law that disproportionately incarcerates people of color is repealed."

Rand Paul's position on criminal justice reform is clear. The shape his message takes on the campaign trail might be a work in progress.

Peyton M. Craighill contributed to this report.