Jeb Bush is promising to draw in more black voters to the Republican Party, but he doesn't seem to know why African Americans tend to vote Democrat in the first place.

On Thursday, Bush contrasted his platform with that of Democrats, who he said get black voters by offering them "free stuff": "Our message is one of hope and aspiration. It isn't one of division, and get in line, and we'll take care of you with free stuff. Our message is one that is uplifting, that says you can achieve earned success. We're on your side."

Bush's comments get the history wrong. Black voters didn't start aligning with Democrats because of "free stuff." They shifted because the party started standing up for issues that matter most to African Americans, including basic civil rights.

This chart, compiled with data from the Joint Center for Political and Economic Studies, shows key moments when a large majority of African Americans began supporting the Democratic Party:

Each big jump correlates with momentum for black civil rights led by Democratic leaders. In 1948, President Harry Truman called for civil rights protections for black Americans, including civil and voting rights protections and federal protection against lynching. In 1964, President Lyndon B. Johnson signed the Civil Rights Act — while Republican Barry Goldwater, who ran for president that year, voted against it. In 1965, Johnson signed the Voting Rights Act of 1965. And in 1968, Richard Nixon, a Republican, ran a presidential campaign based largely on a "Southern strategy" that played up racist fears of black Americans, which Ronald Reagan would also use to win the White House in 1980.

Many Democrats at the time opposed the Civil Rights Act and Voting Rights Act, but these were by and large Southern Democrats who would over time switch to the Republican Party as both parties cemented black civil rights as the Democratic Party's cause. And the most public faces of the Republican Party at the time — such as Nixon and Goldwater — purposely played into conservatives' racist fears.

But it's not just the history that matters. Democrats' claim to black civil rights issues remains true today.

Democrats continue giving more attention to issues that matter most to black voters

The clearest modern demonstration of the Republican-Democratic divide on black civil rights issue is the Black Lives Matter movement, which aims to undo racial disparities in the criminal justice system.

Every major Democratic candidate for president has directly addressed the movement by meeting with representatives from the cause or releasing racial justice platforms. And President Barack Obama has been largely supportive of the movement's cause, calling the criminal justice system an "injustice system" in a speech to the NAACP while outlining the need for reform.

Republican candidates, on the other hand, have ranged from quiet to downright hostile toward the Black Lives Matter movement. Wisconsin Gov. Scott Walker, who just dropped out of the presidential race, blamed Obama and the Black Lives Matter movement for an increase in anti-police rhetoric and violence. Bush, meanwhile, said he met with Black Lives Matter protesters, but it turns out the people he met with didn't represent Black Lives Matter at all. Besides that, the field has been largely mum when it comes to the movement. (There was one question about Black Lives Matter in the two Republican debates so far.)

Of course, black Americans care about far more than the Black Lives Matter movement and racial disparities in the criminal justice system — they cite unemployment and crime as higher priorities than their white counterparts, according to Gallup.

But black Americans are, not surprisingly, more likely than white Americans to pick race relations as the top problem facing the US, and it's their top issue along with unemployment.

So given Republicans' disinterest in and even hostility to these types of issues, it should really be no surprise that more black voters tend to go Democrat.

(Hat tip to the Washington Post's Philip Bump for first pointing out the Joint Center for Political and Economic Studies data.)