A lot of people who have been supporting criminal justice reform for much longer than Hillary Clinton are feeling very conflicted about her speech at Columbia University yesterday embracing the cause. And some are simply angry.

After all, as recently as 2008 Clinton was attacking Barack Obama for his opposition to mandatory minimum sentences, using it as an example that he was too liberal to win the Democratic nomination. And she wasn't exactly a bystander during the "tough on crime" era of the 1980s and '90s that created mass incarceration by putting many more offenders in prison for much longer. Bill Clinton championed a 1994 law that, among other things, has increased untold numbers of prison sentences (by encouraging states to drastically reduce or eliminate parole and early release). And his First Lady was right alongside him. "We need more and tougher prison sentences for repeat offenders," she said in 1994. "We need more prisons to keep violent offenders for as long as it takes to keep them off the streets."

the two questions: why should we believe hillary now? has she learned from her mistakes?

The criticism of Clinton's relatively sudden flip-flop comes from some of the top advocates in the criminal justice reform movement, including the heads of the Drug Policy Alliance and Families Against Mandatory Minimums. Many feel it's foolish to believe that Clinton has a change of heart now, and don't see why they should support her just because of one speech. Others want to see her take more responsibility for her role in creating the problem she now says she wants to solve.

Behind the snark, there are two big questions: Why should we believe Hillary Clinton suddenly cares about criminal justice reform? and Has Hillary Clinton really learned from her mistakes? The first of those actually doesn't matter at all. The second one matters a lot.

It doesn't matter what's in Clinton's heart

Many of the reactions from criminal justice advocates and pro-reform journalists to Clinton's speech (as collected in Storify from David Menschel) simply dismiss her sincerity. Some of these are diplomatically phrased and some less so, like this tweet from longtime criminal justice journalist Liliana Segura, now writing for the Intercept:

So we're just swallowing this bullshit, then? https://t.co/kiAbpe4GoM — Liliana Segura (@LilianaSegura) April 29, 2015

Whenever a politician suddenly flip-flops on an issue, especially after decades spent on the other side, it makes sense to wonder whether the conversion is genuine. But even if Clinton doesn't believe a word she said at Columbia, the fact that she gave the speech is incredibly significant.

For one thing, it's a symbol of how quickly the politics of criminal justice within the Democratic Party have changed. In 2008, Clinton's campaign thought Obama's support for mandatory-minimum reform would hurt him in a Democratic primary. In 2015, Clinton's campaign feels that criminal justice reform (including reform to mandatory minimums) has become such a critical issue to much of the Democratic base that it should be the subject of the very first policy speech Clinton has given since launching her campaign in mid-April. That's a recognition of the power criminal justice reformers have already accrued. In particular, criminal justice has become one of the most important issues (perhaps second only to voting rights) for African-American interest groups, and over the last year the #BlackLivesMatter movement has made it a key issue for progressives, as well.

But the speech didn't just acknowledge how much leverage reformers have right now. It gave them leverage they can use in the future. As political scientist Jonathan Bernstein wrote for the Washington Monthly in 2012 (and Jamelle Bouie of Slate pointed out on Twitter yesterday), research shows that campaign promises are actually a lot more important than you might think:

Jeff Fishel looked at campaigns from John F. Kennedy through Ronald Reagan. What he found was that presidents invariably attempt to carry out their promises; the main reason some pledges are not redeemed is congressional opposition, not presidential flip-flopping.

The question, of course, is what counts as a promise — political insiders and the media are often quick to dismiss things like Clinton's Columbia speech as campaign rhetoric, and that shapes what history remembers as a commitment. But when advocates think a politician has promised them something, it gives them an opportunity to put public pressure on that politician when she doesn't deliver.

Just look at the Obama administration's relationship with immigration reform activists. Few people in Washington actually held it against Obama when he failed to introduce a comprehensive immigration reform bill in his first year in office, even though he'd said he would on the campaign trail. But immigrant activists did, and they resorted to increasingly public protests to hold him accountable — by calling on him to both champion reform and to take executive action. Clinton just handed criminal justice advocates something they can use, if she's elected president, to prove that she told them reform was a priority.

It matters whether she's learned that good intentions aren't enough

The second strain of advocates' criticism of Clinton isn't about whether she believes what she said; it's about whether what she said was enough.

As Ethan Nadelmann, the executive director of the Drug Policy Alliance, wrote for the Huffington Post:

I must admit it also brings up feelings of anger and disappointment at the failure of Hillary Clinton, and other candidates, and so many other ostensible leaders to acknowledge that they were willing and even eager proponents of the very policies that produced America's records-breaking rates of incarceration. The laws and policies we embraced back in the 1980s and 1990s, they're all saying in one way or another, were the right thing at the time -- but now we just need to roll them back now that times have changed.

In this regard, Bill Clinton has been more conciliatory than Hillary. That makes sense, since he's the one who actually signed the 1994 law. Also, he's not running for president. But even the closest thing Bill Clinton's offered to an apology (in an essay book from the Brennan Center about reducing mass incarceration) is still along the lines of "a good thing that went too far":

We acted to address a genuine national crisis. But much has changed since then. It’s time to take a clear-eyed look at what worked, what didn’t, and what produced unintended, long-lasting consequences. So many of these laws worked well, especially those that put more police on the streets. But too many laws were overly broad instead of appropriately tailored.

One problem with this is that the specific claim is wrong: putting more police on the streets did have some effect on the stunning drop in crime we've seen since 1994, but not much, and especially not with violent crime. That's an indication that the Clintons — and more broadly, former "tough-on-crimers" now embracing reform — aren't actually looking at the extensive body of evidence out there about what worked and what didn't.

Beyond specifics, though, the "went too far" narrative implies politicians' erred in the 1990s by simply not thinking hard enough about the needs of the people who've been victimized by mass incarceration. That's also the implication of Hillary Clinton's speech yesterday, which tied the failures of the criminal justice system into a broader narrative of poverty, inequality, and lack of opportunity in black communities. The speech implied that if you cared about black America, you should care about reforming the criminal justice system.

During the tough-on-crime era, however, the opposite was the case: if you cared about black America, it was assumed that you should care about fighting the crime and illegal drug use that was devastating black communities. A majority of the Congressional Black Caucus voted for the 1986 law that created the sentencing disparity between crack and powder cocaine; Congressman Charlie Rangel, in particular, championed the bill and other anti-drug measures. Some civil rights advocates and progressives supported mandatory minimum sentences as a way to reduce judges' racial bias. And in 1994, when President Clinton's crime bill was in jeopardy after a surprising loss on a procedural vote, it was the Congressional Black Caucus that stepped in to save him.

It wasn't that politicians weren't trying to help black America. That's exactly what they were trying to do. The problem is that they were focusing too much on their own intentions, and too little on how the laws they were passing would actually be enforced. The tough-on-crime era is a cautionary tale in how public policy can have unintended consequences.

If Hillary Clinton doesn't actually care about crime policy, she's definitely made it easier for advocates to make her care. If she does care, but she's taken away the lesson that caring is all it takes, that's a bigger problem.