In theory, Bill Clinton should be the perfect surrogate for Hillary Clinton. Only five living men have held the job she’s vying for, and of the select group of living presidents he is the most popular, enjoying a 64 percent favorability rating. Many Americans remember the 1990s under President Clinton as the last time the nation enjoyed peace and sustained prosperity. He put this popularity to good use campaigning for Barack Obama in 2012, when his convention speech and cross-country barnstorming were seen as major assets for the re-election campaign. And if Bill Clinton was such an effective advocate for Obama, shouldn’t he be an even better spokesman for the candidate who has, after all, been his political ally and life partner for more than four decades?

Yet the reality is that Bill Clinton has repeatedly sabotaged his wife’s presidential aspirations, both in 2008 and this year. In 2008, when race was already an incendiary topic given the rise of Barack Obama, the former president kept throwing lit matches onto the woodpile: He said Obama’s victory in South Carolina didn’t amount to much since Jesse Jackson also won there, called Obama’s opposition to the Iraq war “a fairy tale,” and complained that the “race card” was being used against him

Last month he did it again, making what sounded—at best—like a gaffe about Obama by lamenting the “awful legacy” of the last eight years. The former president might have been trying to refer to Republican obstructionism, but it came across as an unfortunate slag against the sitting president, all the more damaging since Hillary Clinton is basing her campaign on a promise to preserve and extend Obama’s legacy. 

Bill Clinton’s sabotage of his wife’s campaign is so recurring a problem that two estimable analysts, Michelle Goldberg at Slate and Rebecca Traister at the New Republic, have both suggested that he be sidelined. “Fire Bill Clinton,” says Goldberg. “Ditch Bill,” Traister advised last May.

The pattern of inadvertent subversion is so persistent that Goldberg speculates it might have psychological roots. It is somehow only when he is working on his wife’s behalf that he veers into sabotage,” she writes. “What is needed here is probably a shrink, not a neurologist. Either he doesn’t want her to overtake him, or he doesn’t want her to repudiate him. Regardless, Hillary should shut him down. She can’t divorce him, but she can fire him.” 

This suggestion of hidden personal motives isn’t entirely unwarranted; in fact, it’s almost impossible to resist, given that the Clintons have the most famous public marriage of our time. Yet the most recent example of Bill Clinton accidentally harming his wife’s campaign, his run-in last Thursday in Philadelphia with Black Lives Matter protesters, suggests the problem is not so much psychological as it is political. 

Bill and Hillary Clinton are in different stages of their political careers, and they have divergent interests. He wants to preserve his legacy, while she is trying to build hers. He is defending what he did as president, while she is trying to win the presidency. He is living in the 1990s, while she is living in the present. 

The contrast between the two Clintons’ agendas became acute at the rally last week when Black Lives Matter protesters held the former president to account for his 1994 crime bill, which the activists blamed (as many justifiably do) for worsening America’s incarceration problem. Bill Clinton responded defensively, using rhetoric that veered all too close to conservative arguments that “black-on-black crime” is the core problem, and focusing on the criminal justice system is a distraction. 

“I don’t know how you would characterize the gang leaders who got 13-year-old kids hopped up on crack and sent them out onto the street to murder other African American children,” he testily remarked. “Maybe you thought they were good citizens. ... You are defending the people who kill the lives you say matter. Tell the truth. You are defending the people who cause young people to go out and take guns.”

By defending the crime bill he signed in 1994, Bill Clinton is undermining his wife’s attempt to win over African-American voters in 2016. The gulf between the two could be seen quite vividly in his defending the concept of “super-predators,” which Hillary Clinton has already apologized for deploying in the 1990s. Black voters have been the indispensable foundation of her campaign to be the Democratic nominee. Without their support, she would be losing to Bernie Sanders. And she has worked hard to prove her mettle to these voters by embracing criminal justice reform and campaigning with the families of victims of police shootings. 

The fissure between the Clintons on this issue is rooted in a shift in Democratic politics. The Democratic Party of the 1990s was very different than it is now, just as America was different. Bill Clinton won the presidency in large part by being able to woo moderate and conservative white voters. In 1992, thanks to a three-way race that included Ross Perot, Clinton won states like Arkansas, Louisiana, and Tennessee. But as politics became increasingly polarized over social issues, such conservative states were no longer in play for the Democrats. Moreover, the broader demographics changed. Non-Hispanic whites were 85 percent of the electorate in 1992. By 2012 they were down to 74 percent, and are likely to drop at least another 2 points in 2016

So Hillary Clinton’s path to the White House will involve winning an electorate that is much more diverse than the one that made her husband president. There’s no use pandering to Deep South whites anymore. Hillary Clinton will only prevail as the nominee in November by replicating the Obama coalition, which is much more liberal and diverse than the 1990s Bill Clinton coalition.

Given this fact, Bill Clinton’s desire to defend his 1990s legacy is a serious problem for Hillary Clinton. There are many areas where his desire to burnish his legacy could hinder his wife’s attempts to hold together today’s Democratic party: Imagine, for starters, Bill Clinton defending NAFTA or financial de-regulation as fiercely as he shot back at the Black Lives Matter protesters on the crime bill. Hillary Clinton might not need to fire him, but she does need to make him realize that her future is more important than his past.